Sen. Lindsey Graham, R-S.C., cautioned any agreement between the U.S. and North Korea is still far away and must eventually be approved by Congress.
Graham made his remarks during a Tuesday interview on "CBS This Morning."
He noted North Korea has not given up anything yet since the two sides only have an agreement in principle.
"Congratulations to President (Donald) Trump for bringing this about," he said. "This is an historic opportunity to end the Korean War, get North Korea to give up weapons and missiles that threaten us and the world in return for security guarantees and prosperity.
"I hope it happens, but there is no agreement. One thing I would tell you, if there is an agreement it must come to Congress for our approval."
And Graham noted the North Koreans have promised before to give up their nuclear program.
"They've done this twice," he said. "Why should we consider this different? I think they believe President Trump is different in this regard -- that if they don't give up their weapons, we're going to have a military conflict to end their program.
"They've got two choices -- column A is security guarantees and economic incentives to give up your nuclear program. Column B is a devastating conflict militarily which they will lose.
"President Trump has to convince Kim Jong Un he's safer and more prosperous without nuclear weapons."
Graham said the Singapore summit was a good start.
But he warned: "We're a long ways away from an agreement.
Graham, in an interview with NBC's "Today" show, said he was not terrible concerned about Trump's decision to halt joint military exercises with South Korea.
"I don't think cancelling a war game is going to matter over the arc of time," he said.
"One thing I would violently disagree with is removing our troops. I can't imagine I would vote for any agreement that requires us to withdraw our forces. That would destabilize Asia. That is what China wants."
© 2022 Newsmax. All rights reserved.