A new White House contingency could mean President Donald Trump may not meet with North Korean leader Kim Jong Un after all.

Trump and his team “must see concrete and verifiable actions” from North Korea toward its pledge to give up its nuclear arms program before any summit will take place, Press Secretary Sarah Huckabee Sanders said Friday.

“They’ve got to follow through on the promises they’ve made,” Sanders said of the North Korean government.

Minutes later, in a statement summarizing Trump’s call on the matter with Chinese President Xi Jinping, the White House referred to the “prospect of dialogue between the United States and North Korea.”

[Analysis: North Korea Deal May Take Years to Nail Down]

The White House’s decision to follow through on the stunning announcement that Trump on Thursday accepted Kim’s invitation for talks via South Korean officials will be made on the basis there are “concrete and verifiable steps.”

Lisa Collins of the Center for Strategic and International Studies said Friday there are “all kinds of questions about how they pull this off in such a short amount of time.”

[Trump Gave Up Nothing In Agreeing to Kim Summit, Pence Says]

“And one critical problem is that there is no lead person in the negotiations with North Korea,” Collins said.

Trump might have someone in mind: Himself.

Sanders left open the possibility that President Trump could act as his own lead negotiator during the summit meeting with Kim Jong Un.

“At the end of the day the ultimate person to lead that negotiation,” she said, “will be the president.”