Senate Majority Leader Mitch McConnell (R-Ky.) says an “arduous” road remains to denuclearization of the Korean Peninsula. (J. Scott Applewhite/AP)

President Trump’s landmark summit with North Korean leader Kim Jong Un drew questions, confusion and cautious warnings from Capitol Hill as lawmakers sought to assert themselves in any nuclear deal Trump may ultimately strike with the reclusive regime. 

Even as they offered measured praise for Trump’s high-stakes diplomatic efforts, congressional Republicans emphasized the difficult road that remains to denuclearization and pressed for more details of what exactly the president agreed to with Kim. 

Sen. Bob Corker (R-Tenn.) said he wanted Secretary of State Mike Pompeo to brief senators on the substance of what the two nations discussed, including whether U.S. troops stationed on the Korean Peninsula would remain. 

“I have no idea” whether Trump secured anything of substance, said Corker, the retiring chairman of the Foreign Relations Committee. “At this juncture, I don’t think we know enough to challenge or celebrate.”

That lack of clarity was underscored by a brief episode Tuesday when Sen. Cory Gardner (R-Colo.) appeared to assert that military exercises with South Korea would continue based on what Vice President Pence told Senate Republicans. Gardner later clarified that he was referring to readiness training drills, not the “war games” in conjunction with South Korea that Trump had said would end. 

Still, the ceasing of the joint military exercises — which Trump called “provocative” — prompted the most pushback from Republican lawmakers as they demanded more information about why the administration had agreed to ending the drills that had so irritated North Koreans. 

“I don’t think that’s wise,” said Sen. Joni Ernst (R-Iowa) of ending the exercises. “We have done these exercises for years with the South Koreans and so I would just ask the president, ‘Why do we need to suspend them?’ They are legal.” 

On Tuesday morning, Trump touted the “very special bond” he said he had forged with Kim and said he was heartened that North Korea had “reaffirmed” its commitment to denuclearization, while providing few specifics about how Kim would back up his promise.

The historic meeting between Trump and the North Korean leader shuffled alliances in other ways on Capitol Hill, as dovish Democrats carefully praised Trump’s diplomatic push. Sen. Bernie Sanders (I-Vt.), while calling the summit “very light on substance,” noted the meeting was a “positive step in de-escalating tensions” between the two countries. 

But other Democrats were sharply critical of Trump’s triumphant claims of a breakthrough in Singapore. 

“With the lack of details, we are worried that Kim Jong Un is getting something for nothing, which is fine for him but not fine for the safety of the citizens of the United States,” said Senate Minority Leader Charles E. Schumer (D-N.Y.). “What the United States has gained is vague and unverifiable. What North Korea has gained is tangible and lasting.”

Yet Republicans who were quick to hammer President Barack Obama for engaging with other rogue nations were more careful in encouraging Trump’s diplomatic efforts. 

“Once North Korea had nuclear weapons, once they have missiles that can deliver them to use, I would liken it to past presidents sitting down with Soviet dictators,” Sen. Tom Cotton (R-Ark.), one of Trump’s closest congressional allies, told the conservative radio host Hugh Hewitt. “It’s not something that we should celebrate. It’s not a pretty sight. But it’s a necessary part of the job to try to protect Americans from a terrible threat.”

Senate Majority Whip John Cornyn (R-Tex.) also said Trump should also get some room to maneuver with Kim, considering the high stakes involved in trying to avert military action on the Korean Peninsula.

“I think the president needs and deserves a little flexibility in negotiating this,” Cornyn said. “The way I look at it is when you’re talking, you’re not fighting. And I think in the interest of everybody involved, that avoiding military conflict is really important if we can — because obviously a lot of innocent people would die in the process.”

It appears likely that Congress will get to weigh in on any North Korea deal in some fashion. The administration has indicated it would do so, and several Republicans, including Sen. Lindsey O. Graham (R-S.C.), said that it would be important for Trump to come to Congress to get approval of an eventual deal to give it a lasting imprimatur.

House Majority Whip Steve Scalise (R-La.) also emphasized the need for congressional approval, citing Obama’s decision not to bring the Iran nuclear agreement to Congress as a formal treaty. Speaking to reporters Tuesday afternoon, Senate Majority Leader Mitch McConnell (R-Ky.) said he preferred that any nuclear deal be submitted as a treaty, which would require two-thirds support for ratification. 

“We all hope this will lead to something,” McConnell said. “We all know for sure that the approaches tried in the past by the Clinton administration, the Bush administration, the Obama administration did not achieve the desirable result, which is to have a denuclearized Korean Peninsula.”

In a statement, Rep. Edward R. Royce (R-Calif.), chairman of the House Foreign Affairs Committee, said he was “glad the president is seeking peace through diplomacy.”

But Royce, who is retiring from Congress, said Kim had “gained much” from Trump’s pledge to suspend military drills and that he was eager to hear specifics about the commitments North Korea had made toward denuclearization.

Sen. Rob Portman (R-Ohio), who had long called for direct dialogue between the United States and North Korea, said he was “skeptical but hopeful” that negotiations started by Trump can lead to North Korea giving up its nuclear weapons.

In a statement, Portman cautioned that in the past, “North Korea has used talks to stall while continuing its nuclear and missile programs, and empty promises cannot buy any more time.”

And Portman, who sought to ensure the release of Otto Warmbier from a North Korea labor camp last year, called that episode “a constant reminder to me about the evil nature of this regime.”

House Minority Whip Steny H. Hoyer (D-Md.) told reporters Tuesday he was concerned that Trump appeared to be cozying up to a murderous dictator under uncertain circumstances just days after spurning America’s closest allies at the Group of 7 conference in Canada. 

“The effort is an important effort,” Hoyer said. “But it is troubling to say the least that the effort is being pursued in such an episodic and non-thoughtful way.”