Live Updates: Final Democratic Debate Before Iowa Caucuses

Responding to CNN's Abby Phillip who noted that US President Donald Trump often pokes fun at his opponents, Joe Biden said he was "prepared" for that.

"I've been the object of his affection now more than anybody else on the stage. I've taken all the hits he can deliver, and I'm getting better in the polls. I have support across the board and I'm not worried about taking on Donald Trump at all", Biden said.

Warren said that “...I took an oath to uphold the Constitution of the United States of America. It says that no one is above the law, that includes the president of the United States.we have an impeachment trial, I will be there because it is my responsibility”.

“I have to be in a position I think of the American people [...] I can’t hold a grudge. I have to be able to not only fight but also heal”, Biden said.

“This is a decency check on our government [...] This is a patriotism check. Not only is this trial that, but also this election. And no matter if you agree with everyone on the stage, I say this to Americans, you know this is a decency check on this president”, Klobuchar said.

An hour and a half into the debate, Bernie Sanders is the most-attacked candidate and Amy Klobuchar has delivered the most attacks. #DemDebatehttps://t.co/ecYX2RPTAM pic.twitter.com/Xrs8cLVRyz

— NBC News Graphics (@NBCNewsGraphics) January 15, 2020

“It makes no sense for child care to cost two-thirds of somebody’s income [...] We have to drive it to 7 percent or below. And zero for the families who are living in poverty”, Buttigieg said.

Warren commented in personal terms about the issue.

“If I hadn’t been saved by my aunt, I was ready to quit my job [...] I think about how many women of my generation got knocked off the track and never got back on”, Warren said.

Biden said he believed that “people who are not able to afford any of the infant care to be able to get that care,” referenced his experience raising two sons after his wife and a baby daughter were killed in a 1972 car crash. ”I was a single parent too [...] When my wife and daughter were killed, my two boys I had to raise, I was a senator, a young senator”, Biden said.

"Hundreds of billions of dollars of subsidies for the fossil fuel industry. Tax breaks for billionaires and then tell moms and dads, we cannot have high-quality affordable child care. That is wrong", Sanders said.

Bernie Sanders now leads all candidates in talking time https://t.co/sGefCR4ztI pic.twitter.com/B5zOKhg4Ic

— NBC News Graphics (@NBCNewsGraphics) January 15, 2020

Warren vowed to use all the power as president “has in her” arsenal to lower prescription drug prices.

Klobuchar echoed Warren's comment about using the president’s powers to reduce prescription drug prices.

Biden, Sanders and Warren clashed over “Medicare-for-all" topic.

“I think we need to be candid with voters and tell them what it will cost”, Biden said.

“What I will tell you is Medicare for all which will guarantee comprehensive health care to every man, woman and child will cost substantially less than the status quo”, Sanders said, after dodging a question about the overall costs of his health care proposal.

Warren expressed her allegiance to the Affordable Care Act.

“I will defend the Affordable Care Act [...]I have a plan to expand health care. When we come to a general election, we may argue among each other about the best way to do health care. We’re going to be up against a Republican incumbent who has cut health care for millions of people in and still trying to do that”, Warren said.

Buttigieg told moderators about his plan, stressing that the goal of his plan was to make “sure that there is no such thing as an uninsured American. Because the system doesn’t work...".

Klobuchar lambasted Sanders for not accounting for the cost of all his plans. “I think you should show how you’re going to pay for things, Bernie”, Klobuchar said.

Tom Steyer said Americans spend "too much" on health care "because corporations own the system". "...We've given tax cuts to the richest Americans and the biggest corporations for decades. That's all this is. We have corporations who are having their way with the American people and people are suffering", Steyer said.

We're tracking speaking times live during tonight's #DemDebate. Here's who has spoken the most so far: https://t.co/oteZpey5mW pic.twitter.com/F6wJdVr5um

— CNN Politics (@CNNPolitics) January 15, 2020

Sanders defended his opposition to the USMCA North American trade deal  “We can do much better than a Trump-led trade deal”, Sanders said, pivoting to climate change "Every environmental organization in this country, including the Sunrise organization, who is supporting my candidacy, opposes it”.

Warren argued that the USMCA should be seen as the first step toward getting a better deal.

Sanders denied making such a comment - a woman could not be elected president - that Warren had attributed to him.

“Well, as a matter of fact, I didn’t say it [...] And I don’t want to waste a whole lot of time on this, because this is what Donald Trump and maybe some of the media want", Sanders said.

Warren replied that “the only people on this stage who have won every single election that they’ve been in are the women: Amy and me [...] And the only person who has beaten an incumbent Republican any time in the past 30 years is me”.

Buttigieg and Klobuchar echoed each other saying that they would preserve the 2015 Joint Comprehensive Plan of Action (JCPOA). Buttigieg suggested that walk away from the nuclear deal "set off the chain of events that we’re now dealing with as it escalates even closer to the brink of outright war".

Both Biden and Steyer said they would not meet with North Korean leader Kim Jong Un without any preconditions.

Why is Steyer still wearing his Christmas tie? #DemDebate

— Berniebae🌹🎌🇺🇸🐦🕊️ (@lala6177) January 15, 2020

The question on Iran highlights heightened tensions between Washington and Tehran and Iran. After a US airstrike killed Iranian top general Qasem Soleimani, Tehran declared it would no longer limit itself to the restrictions contained in the Iran nuclear deal, which the Trum administration had previously withdrawn from.

"Ensuring that Iran does not develop nuclear weapons will, of course, be a priority, because it's such an important part of keeping America safe [...] But unfortunately, President Trump has made it much harder for the next president to achieve that goal. By gutting the Iran nuclear deal - one that, by the way, the Trump administration itself admitted was working, certified that it was preventing progress towards a nuclear Iran — by gutting that, they have made the region more dangerous and set off the chain of events that we are now dealing with as it escalates even closer to the brink of outright war", Buttigieg said.

“What we have to face as a nation is that the two great foreign policy disasters of our lifetimes, with the war in Vietnam and the war in Iraq. Both of those wars were based on lies”, Sanders said, adding that he feared Trump could lead the nation into another war amid tensions with Iran.

“I was part of that deal to get the nuclear agreement with Iran, bringing together the rest of the world, including some of the folks who aren’t friendly to us [...] And it was working”, Biden noted.

Klobuchar echoed Buttigieg comments, adding that she also would not Iran to develop nuclear weapons.

Warren, Buttigieg and Sanders suggested they would withdraw US military personnel from Iraq, while Klobuchar and Biden said they would leave some troops in place.

Joe Biden commented on the latest escalation between Washington and Tehran.

"We're in a situation where our allies in Europe are making a comparison between the United States and Iran, saying both ought to stand down, making a moral equivalence. We have lost our standing in the region. We have lost the support of our allies. The next president has to be able to pull those folks back together, re-establish our alliances and insist that Iran go back into the agreement, which I believe with the pressure applied as we put on before, we can get done", Biden said, adding that he would leave American troops in the Middle East.

Senator Bernie Sanders cited foreign policy and Iraq: "I not only voted against the war, I helped lead the effort against that war".

Joe Biden defended his 17-year-old vote.

"I said 13 years ago it was a mistake to give the president the authority to go to war [...] It was a mistake, I acknowledged that”, Biden said, mentioning that Barack Obama opposed the war from the state. “I think my record overall on everything I’ve ever done, I’m prepared to compare it to anybody on this stage”, Biden stressed.

Senator Amy Klobuchar slammed Donald Trump

“What we should be talking about is what is happening right now with Donald Trump [...] Donald Trump is taking us pell mell toward another war”, Klobuchar said.

Buttigieg touted his “difference perspective”, sterssing that the next US president will face unprecedented foreign policy challenges like cyber security issues and climate-driven challenges.

The candidates are being introduced.