U.S. Trade Representative Robert Lighthizer told lawmakers that he wasn’t optimistic a Nafta agreement could be completed by Thursday or in the immediate term, two Democratic representatives said on Wednesday.

That all but guarantees that a deadline cited by House Speaker Paul Ryan will be missed.

“He was not optimistic this was all going to get wrapped up in the next 24 hours, to be sure,” said Representative Ron Kind of Wisconsin, the chairman emeritus of the New Democrat Coalition, referring to Lighthizer. Kind was one of about 35 members of Congress who met with the trade representative. “He felt there was some back-sliding going on with Mexico, and Canada, to a certain extent,” Kind added.

Kind said Lighthizer was “hopeful” that he can rebalance trade to ensure bipartisan support. “We also told him, look, listen, it’s more important to get a good negotiated agreement, rather than a fast one.”

“These trade deals, as you know, are always difficult in the best of circumstances” and that the expectations can seem “an almost impossible lift” even in a lame duck session, Kind said.

Representative Gerald Connolly, a Virginia Democrat, also said that Lighthizer “indicated it is unlikely that an agreement would be reached by tomorrow.”

Lighthizer’s office did not immediately respond to a request for comment.

The development doesn’t mean the Nafta talks are dead—they will continue, and the existing deal remains in force. But the window to pass it in the current Congress is closing as U.S. attention shifts to other priorities.

Lighthizer is scheduled to attend meetings Thursday and Friday with China’s Vice Premier Liu He over trade disputes with Beijing. He has not met with his Nafta counterparts since last week and still faces big gaps on key issues.

Ryan has said that under American trade law, Thursday was the last day to receive notice of intent to sign a new agreement that could be passed by the current Congress.

“An awful lot of things would have to go right in order for this to be voted on in this Congress,” said Eric Miller, a Washington-based trade adviser and Woodrow Wilson Center fellow.

Good Deal Needed

Earlier Wednesday, Mexican Economy Minister Ildefonso Guajardo said a deal by Thursday was practically impossible, but it was possible to reach one later this month or early June and still pass it under the current U.S. Congress. Canadian Foreign Affairs Minister Chrystia Freeland’s spokesman called the deadline a U.S. issue.

One Canadian official, speaking on condition of anonymity, said it will be up to President Donald Trump to decide whether he wants a compromise deal now, or if he’d rather hold out for something better in the next Congress, when a new crop of lawmakers could change the political calculus.