Members of the US Senate met behind closed doors Saturday to hash out an agreement that would fully fund the federal government and bring an end to the partial shutdown that began at midnight.

Majority Leader Mitch McConnell opened the unusual Saturday session with a speech scolding Democrats for their refusal to vote for a budget measure that includes funds for President Trump’s long-promised border wall.

“One would think that protecting the American people would be a non-partisan issue,” he said, pointing out that Democrats–including Senate Minority Leader Chuck Schumer–have voted in favor of a physical barrier on the US-Mexico border in the past.

Trump revealed his own negotiation plans in a Saturday tweet.

“Will be having lunch in White House residence with large group concerning Border Security,” he stated just after noon. He did not specify the invitees.

A final vote on a budget agreement is not expected until Sunday at the earliest, because members of the House — who would have to approve any Senate deal that differs from the funding bill they passed Thursday — have been promised a 24-hour warning by the Republican leadership.

About a quarter of the government shut down Friday, with the Senate at loggerheads over Trump’s insistence on $5 billion in funding for a wall on the nation’s southern border.

The House’s spending bill, which would fund federal agencies, including the Department of Homeland Security, allocates $5.7 billion for border-security — but the measure would need 60 votes, including from some Democrats, to pass the Senate.