WASHINGTON (AP) — The fight over President Donald Trump's $5 billion wall funds has deepened, threatening a partial government shutdown in a standoff that has become increasingly common in Washington.

It wasn't always like this, with Congress and the White House at a crisis over government funding. The House and Senate used to pass annual appropriation bills, and the president signed them into law. But in recent years the shutdown scenario has become so routine that it raises the question: Have shutdowns as a negotiating tool lost their punch?

Monday brought few signs of progress. A partial shutdown that could occur at midnight Friday risks disrupting government operations and leaving hundreds of thousands of federal employees furloughed or working without pay over the holiday season. Costs would be likely in the billions of dollars.

Trump was meeting with his team and getting regular updates, said White House spokeswoman Sarah Huckabee Sanders. Trump was also tweeting Monday to keep up the pressure.

Exiting a Senate Republican leadership meeting late Monday, Sen. John Thune of South Dakota said, "It looks like it probably is going to have to build for a few days here before there's a solution."