Republicans dodged a government shutdown in October, but December is a different story, House Speaker Paul Ryan, R-Wis., suggested Monday, because of President Trump’s battle to win money for a southern border wall.

Ryan told reporters at the National Press Club he couldn’t guarantee government funding won’t expire for some parts of the federal government that are temporarily funded through mid-December.

“We intend on having a full-fledged discussion on how to complete our mission to secure the border and yes, we will have a fight about this,” Ryan told reporters.

Ryan said lawmakers have not determined how to resolve differences over the wall funding.

A House Homeland Security appropriations bill provides $5 billion in funding, but the Senate version includes $1.6 billion. President Trump’s fiscal 2019 budget calls for $1.6 billion, but he is now calling for an unspecified but significant increase.

The department is funded only until mid-December and at fiscal 2018 levels.

The president has repeatedly threatened to reject pending bills after the election unless they include significant funding for a wall.

Ryan said he’s not sure how it will get resolved.

“Republicans must finally get tough!” Trump warned in a Sept. 20 tweet that criticized a “ridiculous” spending bill he signed into law that did not include wall funding.

While the House can pass legislation with GOP-only votes, the Senate will require the help of at least nine Democrats to pass spending measures thanks to the filibuster rule.

Democrats are nearly universally opposed to significant wall funding, which they believe is wasteful spending. If the two sides can’t agree, the bill will have to exclude wall funding in order to pass, or else funding would lapse at least at the Homeland Security Department.

“We will figure out how to do it in December,” Ryan said. “I can’t speak to what the outcome will be, only that the effort is there.”