National Economic Council Director Larry Kudlow said President Trump could decide as soon as Wedneday whether to close the U.S. border with Mexico, signaling that internal discussions have reached an advanced stage and that top aides are now waiting for a presidential directive.

Kudlow said, though, that there is no concrete time frame, and that they are planning for a range of scenarios based on what Trump orders.

“The president will give us his views today or as days go by,” Kudlow told reporters at a breakfast hosted by the Christian Science Monitor.

In the past week, Trump has escalated threats to completely or partially seal off the U.S. border with Mexico to address a surge of families and other migrants attempting to cross into the United States.

Kudlow and other White House advisers have discussed ways to blunt the economic damage from such a move, worried that it could severely affect the United States.

“The president has not made a decision yet, as you know — at least I’m not aware that he has,” Kudlow said.

More than $1 billion in goods moves across the U.S. border with Mexico each day, and many U.S. companies rely on materials or agricultural products from Mexico for their domestic businesses.

White House officials are considering ways to allow trucks and trains to continue moving across the border, even if passenger vehicles and pedestrians are stopped. Even those exemptions, Kudlow said, would not prevent an economic mess. He noted that many workers and tourists cross the border every day, and the impact could be quickly felt.

“Anything we could do to ameliorate the economic story is being looked at very carefully,” he said.

He said he has talked with officials from the Department of Homeland Security about the best ways to help commercial trade in the event that Trump tries to seal off the border.

“We’re very integrated with the Mexican economy,” he said.

Separately, Kudlow said Trump remains fully committed to nominating conservative economist Stephen Moore to the board of the Federal Reserve. Several recent news articles have raised questions about Moore’s behavior during divorce proceedings several years ago, and he also faced a tax lien because he owed $75,000 in taxes to the Internal Revenue Service.

But Kudlow said he discussed Moore’s candidacy with Trump on Tuesday, and the president was unwavering.

“He continues to support Steve,” Kudlow said. “I certainly do. People are being awfully hard on him. This town is a toxic town in some respects. We are fully behind him.”

Trump has not yet formally nominated Moore, but he has announced that he will. If confirmed by the Senate, Moore would fill one of the seven seats on the Fed’s board, giving him a vote and other input regarding interest rate policy, among other things.

Moore has echoed Trump’s demands for lower interest rates, which late last year appeared to run counter to the Fed’s agenda, which was being led by Chair Jerome H. Powell. But the Fed has recently announced plans to pause interest rate increases.

The Wall Street Journal reported Tuesday that Trump and Powell recently spoke on the telephone — a rare occurrence — and that Trump acknowledged to Powell that he was “stuck” with him at the central bank.

Kudlow said Wednesday that he wasn’t with the president during the phone call but tried to assuage fears that the conversation amounted to presidential arm-twisting.

“The president may have said that lovingly,” Kudlow said, adding that it might have been an “affectionate, huggy thing on the phone.”