Trump made his position clear at a White House meeting with both parties' congressional leaders, agreeing with Senate Minority Leader Charles Schumer and House Minority Leader Nancy Pelosi on plans for a bill to fund the government and raise the debt ceiling for three months.
That effectively postpones until December a divisive fight over financial matters, including whether to fund construction of Trump's long-promised wall at the US-Mexico border.
"We had a very good meeting with Nancy Pelosi and Chuck Schumer," Trump told reporters on board Air Force One as he travelled to North Dakota. "We agreed to a three-month extension on debt ceiling, which they consider to be sacred - very important - always we'll agree on debt ceiling automatically because of the importance of it."
In siding with Democrats, Trump overruled his own treasury secretary, Steven Mnuchin, who was in the middle of an explanation backing a longer-term increase when the President interrupted him and disagreed, according to a person briefed on the meeting. Trump was "in deal-cutting mode," the person said.
After the gathering, McConnell said he would add provisions extending government funding and the debt limit through to mid-December to legislation passed by the House today providing US$7.85 billion in Hurricane Harvey relief.
"The President agreed with Senator Schumer and Congresswoman Pelosi to do a three-month [funding extension] and a debt ceiling into December, and that's what I will be offering, based on the President's decision, to the bill," McConnell told reporters. "The President can speak for himself, but his feeling was that we needed to come together to not create a picture of divisiveness at a time of genuine national crisis."
Trump also threw tacit support behind the Democrats' push for a "Dreamers" bill that would effectively formalise an Obama-era programme shielding undocumented immigrants brought to the United States as children from deportation.
Trump yesterday began phasing out the Deferred Action for Childhood Arrivals programme, which GOP hard-liners regard as illegal amnesty, but suggested today that if Congress passed a Dreamers bill he might sign it.
"Chuck and Nancy want to see something happen - and so do I," Trump said.
By setting up another debt-ceiling vote in December - a vote in which Republicans will almost certainly need Democratic help to avoid default - Democrats keep their seat at the table in this autumn's key policy debates.
Had Trump sided with GOP leaders, Democrats would have been stuck trying to extract concessions ahead of debt-ceiling votes this week using an empty threat - voting against a legislative package that includes the politically sensitive Harvey aid. Democrats believe pushing the debt-limit debate into December will increase their leverage on several issues, including the protection of Dreamers and securing funds to help stabilise healthcare markets.
Schumer and Pelosi also gained an edge by giving Democrats an aura of strategic command they have lacked since Trump's election. Instead of McConnell claiming victory, it was Schumer who told reporters, "The nation can breathe a sigh of relief".
The deal may also benefit Trump by allowing him to revive his threat to shut down the government over wall funding.
At the White House, Republican leaders pushed for an 18-month debt-limit hike, then floated doing a six-month extension, according to two aides briefed on the meeting. But Pelosi and Schumer dismissed the six-month proposal, and Trump then agreed to the three-month hike that Democrats put on the table.
McConnell and Ryan came out of the White House meeting in the weakest position - losing an opportunity to neutralise the debt-ceiling issue before the 2018 midterm elections and to exclude Democrats from major policy debates this year.
The President's decision came barely an hour after Ryan panned the idea of a short-term debt hike, accusing Democrats of "playing politics" with much-needed aid for Hurricane Harvey victims.
"I think that's ridiculous and disgraceful that they want to play politics with the debt ceiling at this moment when we have fellow citizens in need," Ryan told reporters.
Trump apparently disagreed.
"We essentially came to a deal, and I think the deal will be very good," Trump said. "We had a very, very cordial and professional meeting."
Not all Democrats were so thrilled with the deal. Some were upset it did not include protections for the estimated 800,000 Dreamers.
"So Trump attacks our Dreamers and the next day the Democrats walk in there and say, 'Oh, let's just have a nice timeout,' while they're all suffering?" said Congressman Luis Gutiérrez. "That is what is wrong with Democrats. They don't stand up."
Schumer said he was not finished advocating for Dreamers. "This is not a trade-off for us," he said. "This is a very important issue that we're going to fight hard for until we get it done."
