Vice President Mike Pence told US ambassadors Wednesday that North Korea has failed to take any substantive steps to give up its nuclear weapons, even as President Donald Trump is moving toward a second meeting with Kim Jong Un, the North Korean leader.

“While the president has started a promising dialogue with Chairman Kim,” Pence told the gathering at the State Department, “we still await concrete steps by North Korea to dismantle the nuclear weapons that threaten our people and our allies in the region.”

With the unequivocal statement, Pence seemed to directly contradict the president’s claim on Twitter, after his first summit meeting in June, that “there is no longer a Nuclear Threat from North Korea.” At the time, many of Trump’s top aides cringed at the declaration, fearing it would take the economic pressure off the North to disarm.

The United States and North Korea plan to hold high-level talks in Washington as soon as this week to discuss a second summit of their leaders, following a prolonged stalemate in nuclear talks, South Korean media said on Tuesday.

The timing of Pence’s comments was significant, coming just before Pyongyang’s lead negotiator over the nuclear program, Kim Yong Chol, is expected to arrive in Washington to meet on Friday with Secretary of State Mike Pompeo. The North Korean negotiator is usually not permitted to travel more than a short distance from the U.N. headquarters in New York, where Pompeo met him last year, so the invitation to Washington was seen as a gesture to make arrangements for the summit meeting.

While the United States has demanded that North Korea turn over its nuclear weapons before it sees any significant sanctions relief, the North has argued for a step-by-step approach including that the United States withdraw troops and weapons from the Korean Peninsula.

Breaking that logjam will be the key to the meeting with Pompeo, US officials said. North Korea has still not taken the first step demanded by the United States: providing an inventory of its nuclear weapons, its stockpiles of nuclear material, its production facilities, missile fabrication plans and launch sites.

Kim, the negotiator, is expected to bring a letter from Kim Jong Un about the proposed second summit meeting with the president. Trump has taken to collecting past correspondence and showing it off to journalists, among others, in the Oval Office.