WASHINGTON (Reuters) - When the U.S. Congress reconvenes on Nov. 13, it will face a deadline less than a month later to fund parts of the federal government and a possible showdown over money for President Donald Trump’s proposed U.S.-Mexico border wall.

U.S. border patrol agents ride past the U.S.-Mexico border wall on horseback near San Diego, California, U.S. May 7, 2018. REUTERS/Mike Blake

Taking a confrontational position on the issue, Trump said at a news conference on Wednesday he could not commit to avoiding a partial government shutdown if Congress refuses to provide him all the funding he wants for his wall.

“We need the money to build the wall, the whole wall, not pieces of it,” Trump told reporters, days before Congress reconvenes for its mid-November to mid-December “lame duck” session.

Trump has issued ultimatums about wall funding before, with little impact, even with his own Republican Party in majority control of both the Senate and the House of Representatives.

Even though Tuesday’s congressional elections gave the Democrats majority control of the House, the Republicans will still control both chambers until January.

That means that they will need Democratic support for any funding bills in the Senate, where Republicans have 51 of 100 seats. They will need 60 votes to advance legislation.

Having won control of the House in the elections, Democrats said they will be even less motivated than before to meet Trump’s wall demands.

If the two parties cannot reach a funding deal, there would be a partial government shutdown, with so-called “essential services,” including some at the Department of Homeland Security, likely remaining in operation.

“We need to work this out,” Senate Republican leader Mitch McConnell said on Wednesday. “Seventy-five percent of the government was funded before the end of September.”

Lawmakers reached a bipartisan agreement in September to fund much of the federal government. The fight over money for the wall was delayed until after the elections by including only temporary funding until Dec. 8 for some government services, including Homeland Security.

“We’re going to do the best we can to try to achieve the president’s priorities and hopefully we will not be headed down that path,” McConnell said of a partial shutdown.

He said Congress would also try to finalize a five-year reauthorization of the farm bill during the “lame duck” session. The legislation expired at the end of September but most of its programs remain in place through the end of the year.