President Donald Trump hasn’t set a date to meet his Chinese counterpart Xi Jinping as the world’s two biggest economies continue negotiations to end a trade war, said White House spokeswoman Sarah Huckabee Sanders.

Trump has said he’ll need to meet Xi to conclude any agreement over trade. White House economic adviser Larry Kudlow on Sunday said he was “optimistic” the two leaders would meet at some point, possibly this month or next. His comments followed reports that Chinese officials canceled a trip to Trump’s Mar-a-Lago resort for a potential signing ceremony.

Trump has repeatedly, even as recently as last week, hailed progress in the trade discussions, but he’s also threatened to walk away if he can’t get a good enough deal.

“He’s going to make a deal if it’s in the best interest of America,” Sanders told reporters in Washington on Monday. “If he doesn’t feel like it’s a good deal, it’s not worth just signing a piece of paper.”

The president is committed to an agreement that addresses China’s treatment of U.S. intellectual property and has an enforcement mechanism to ensure that Beijing is following through on its end of the bargain, she said.

Trump, who has slapped tariffs on at least US$250 billion of Chinese goods since last year, has delayed an escalation of the duties while the sides keep trying to hammer out an agreement.

“We’re continuing the negotiations with China,” Sanders said. “When we have an announcement for the two leaders to sit down, we’ll certainly let you know."