Ramaswamy has already notified his team of his decision.
"We are going to suspend this presidential campaign and this is going to have to be, there is no path for me to be the next president," Ramaswamy said in Des Moines headquarters on Monday.
As ex-President Donald Trump continues to maintain the lead in Iowa votes at 51% as tabulation is wrapping up, Ramaswamy, who secured 7%, endorsed the fellow Republican for president.
"I congratulate him on his victory, and now going forward, you will have my full endorsement for the presidency,” Ramaswamy said.
Asked whether he would be vice president to Trump if he wins, Ramaswamy said that he would "do whatever is right for the country."
Earlier, Vivek Ramaswamy during the fourth Republican primary presidential debate said that the Ukraine conflict is pointless and slammed former South Carolina Governor Nikki Haley for not backing efforts to reach a peace deal.
Ramaswamy has been very vocal about his unwillingness to provide more aid for Ukraine if elected president; at the first Republican debate in August, he was the only candidate who said he would not support providing additional funding for Ukraine.