Members of Congress tentatively approved of President Donald Trump's move Thursday to cancel his planned summit with North Korean dictator Kim Jong Un — but questioned where the president will go from here. Some Republican lawmakers saw the meeting as potentially treacherous or doomed to fail and expressed suspicion about Kim's intentions for coming to the table. Trump had planned to push North Korea to give up its nuclear and missile programs during the summit. Certain members of Congress urged Trump not to give up on those efforts to seek peace with Pyongyang. Some Democrats, however, worried about whether Trump had a plan moving forward, and warned him not to go back to the aggressive rhetoric he employed toward North Korea at times last year. Here are some of the reactions from notable lawmakers:

House Speaker Paul Ryan

In a statement, House Speaker Paul Ryan on Thursday questioned North Korea's intentions. The Wisconsin Republican pushed Trump to keep up the economic pressure campaign carried out through international sanctions. "The North Korean regime has long given ample reason to question its commitment to stability. We must continue to work with our allies toward a peaceful resolution, but that will require a much greater degree of seriousness from the Kim regime. At the same time, Congress has provided significant tools to hold North Korea accountable, and it is important that the United States not relent in this maximum pressure campaign."

House Minority Leader Nancy Pelosi

Nancy Pelosi, the top House Democrat, called scrapping the meeting "a good thing for Kim Jong Un." The California Democrat said the "thug" Kim is "the big winner" after getting "legitimized" by Trump. "This takes preparation ... which the president didn't make. It's clear he didn't know what he was getting into. And now he's walking away from it," she said.

Senate Majority Leader Mitch McConnell

"I think [Trump] did the right thing" in canceling the summit, Senate Majority Leader Mitch McConnell, R-Ky., told reporters.

Senate Minority Leader Chuck Schumer

Top Senate Democrat Chuck Schumer said Thursday he worried the summit would not have yielded real results. The New York senator urged Trump to achieve a "concrete, verifiable" end to Kim's nuclear program if another summit takes place. "The fear many of us had was that the summit between President Trump and Kim Jong Un would be a great show that produced nothing endured. If a summit is to be reconstituted, the United States must show strength and achieve a concrete, verifiable enduring elimination of Kim Jong Un's nuclear capabilities," he said on the Senate floor.

Rep. Ed Royce, House Foreign Affairs Committee chair

Rep. Ed Royce, R-Calif., urged Trump to "continue to look for opportunities while applying maximum diplomatic pressure." "Our goal is to peacefully end North Korea's nuclear threats. The administration should continue to look for opportunities while applying maximum diplomatic and financial pressure against Kim Jong Un. Our allies — including South Korea and Japan — need to stand with the United States. There can be no daylight between us."

Sen. Bob Menendez, Senate Foreign Relations Committee ranking member

Sen. Bob Menendez, the top Democrat on the Senate Foreign Relations Committee, said Thursday that "the art of diplomacy is a lot harder than the art of the deal." During a hearing, the New Jersey lawmaker called it "pretty amazing" that the Trump administration "might be shocked that North Korea is acting as North Korea might very well normally act." "And while we applaud the robust diplomatic efforts to try to denuclearize the Korean Peninsula, many of us were deeply concerned that the lack of deep preparation that is necessary, before such a summit is even agreed to, was not taking place," he said.

Sen. Ben Cardin, Senate Foreign Relations Committee member

Speaking to reporters Thursday, Sen. Ben Cardin, D-Md., called Trump's decision to walk away from the summit "puzzling," according to NBC News. He added that he has not seen anything to date that would change the need for direct talks between Washington and Pyongyang.

Sen. Marco Rubio, Senate Intelligence Committee member

In a tweet Thursday, Sen. Marco Rubio, R-Fla., called Trump's move "100% the right decision." He argued Kim "doesn't want a deal." "He has deliberately sabotaged the talks over the last two weeks & was setting us up to take the blame," Rubio wrote. Rubio tweet

Rep. Eric Swalwell, House Intelligence Committee member