In a response to an NBC report which said that US intelligence believes North Korea has been producing more nuclear fuel at undisclosed facilities in recent months despite its pledge to scrap nukes, Murphy tweeted:
"This can’t be true!!!” adding that US President Donald Trump had reassured his compatriots that Pyongyang no longer posed a nuclear threat and said "he took care of it.”
The senator, who is an open critic of Trump, was saying this in reference to comments that Trump made after he met with North Korean leader Kim Jong-un.
"Everybody can now feel much safer than the day I took office. There is no longer a Nuclear Threat from North Korea," Trump tweeted shortly after meeting with the North Korean leader.
The report comes amid a general thaw between the DPRK and the United States, which culminated in a historic meeting between their respective leaders in Singapore earlier this month.
However, the US Central Intelligence Agency, which has reportedly increased spying efforts in North Korea, claims that production of weapons-grade enriched uranium has been increasing.
Moreover, skeptics of the meeting noted that Trump signed an agreement that provided concessions without receiving a solid commitment to a timeline and method for irreversible denuclearization from the DPRK.
They also pointed out that North Korea has made similar agreements in the past, only to later change their conduct.
Currently, North Korea has only one declared enrichment facility at Yongbyon, according to NBC, but sources told the broadcaster that there seemed to be more than one unreported site.