WASHINGTON -- A standoff over how to prevent a government shutdown intensified Monday as President Donald Trump called on Republicans to write a funding bill on their own and cut Democrats out of the process.

But any funding bill, including a stopgap to buy more time, requires 60 votes to pass the Senate, where Republicans control 53 seats and therefore need at least seven Democratic votes.

Democratic leaders say Republicans are following Trump's wishes and are refusing to negotiate, making a shutdown more likely. Congress has until 11:59 p.m. on Sept. 30 to find a solution or the government will shut down.

"Our position remains this: We want to keep the government open by engaging in bipartisan negotiation where we can address some of the grave harms Donald Trump has caused to our health care system and help Americans with the cost of living," Senate Minority Leader Chuck Schumer, D-N.Y., said on the floor Monday evening.

Trump said recently on "Fox and Friends" that Republicans should not "even bother" with Democrats and that "we have to get Republican votes, that's all" -- which Schumer condemned.

"When Donald Trump said on Fox News that Republicans, "don't even bother" dealing with Democrats, then he's responsible for making a shutdown more likely," he said. "This afternoon he doubled down again, posting online that Republicans should go at it alone in their partisan CR. Instead of engaging with Democrats to keep the government open."

Schumer argued that if there is a shutdown, Trump's statement and GOP actions would make them the responsible party. "If one side refuses to negotiate, they are the ones causing the shutdown," he said.

Senate Majority Leader John Thune, R-S.D., said that the Republican-controlled Congress will try to pass a seven-week funding bill at existing spending levels to give the parties more time to negotiate. Democrats should get on board, he said, in order to avert a funding lapse.

"We will be putting forward a clean resolution to ensure there is no reason for Democrats to oppose this bill and delay passage," Thune said Monday. "And my hope would be that we could get this done as soon as this week and then continue bipartisan work on appropriations bills."

"But I have some concerns," the majority leader added. "Because incredible as it may seem, Democrats seem to be looking to shut down the government."

Democrats have not laid out a specific set of demands that would win their votes for a funding bill, apart from emphasizing they want changes in the health care system. The party is divided on how aggressive to be, with some pushing for an extension of expiring Obamacare subsidies and others saying they should also demand a rollback of Trump's Medicaid cuts in his "big, beautiful bill." And underneath the jousting is a reluctance on the part of some Democrats to allow a shutdown, which would be economically harmful.

The first step would be to pass a short-term funding bill in the House, where Republicans can afford just two defections in their wafer-thin majority before requiring Democratic support. And they may need multiple Democrats to vote aye; there are already several GOP lawmakers who say they oppose any short-term funding bill, known as a continuing resolution or "CR" -- including Reps. Thomas Massie, R-Ky., Marjorie Taylor Greene, R-Ga., Warren Davidson, R-Ohio.

"This CR would be a copy of the uniparty spending bill under Autopen Biden," Massie wrote on X. "I didn't vote for those spending priorities when Biden was President and I won't vote for them now."

Davidson said: "I already hated status quo thinking and approaches (soft incrementalism at best), so I'm out on another CR for the sake of more government."

Greene said it would betray Trump. "I can't wait to see how voting for the CR becomes a Trump loyalty test," she wrote on X. "When in all actual reality, it's a disloyalty to him by passing a Biden policy laden omnibus."

Others are skeptical, too.

"It's gonna have problems," Rep. Andy Harris, R-Md., the chair of the hard-right Freedom Caucus, said of a seven-week stopgap bill at existing spending levels.

Rep. Tim Burchett, R-Tenn., told NBC News, "I wish leadership would come talk to us. I see where they've talked about how, 'We've cut this deal.' Well, they haven't cut a deal with membership. And I know four 'no' votes on the Republican side right now."

Trump called on the House GOP to unify and back the measure.

"In times like these, Republicans have to stick TOGETHER to fight back against the Radical Left Democrat demands, and vote 'YES!' on both Votes needed to pass a Clean CR this week out of the House of Representatives," Trump wrote on social media.

If the legislation does pass the House, where it needs a simple majority, it will set up a showdown in the Senate pitting Republicans against the Democratic minority. So far, just one Democrat has said they'll support a continuing resolution: Sen. John Fetterman, D-Pa.

"I've always had the same hard rule: Don't ever shut the government down ... or hold keeping the government open as a hostage," Fetterman told NBC News.

He said he "fully" supports extending ACA funding as well.

"That should be a standalone thing, that's not like, 'I'm gonna shut our government down,'" he said. "It's a trap. It's the wrong thing to do. ... Our nation doesn't need more chaos right now, in shutting the government down. That is the wrong answer. ... It's dangerous right now."

But Sen. Ruben Gallego, D-Ariz., said he's very skeptical of a short-term bill unless it addresses health care costs.

"I'd have to hear some really, really good reasons -- of what is that going to produce," he said in an interview. "And how is that going to contribute to a bipartisan solution that's going to bring Americans' premiums down."

Trump tells GOP to cut out Democrats on funding bill as Schumer warns of shutdown