Joe Biden insisted Democrats would pass his ambitious domestic spending agenda despite interparty feuding that has stymied its passage, saying “we’re going to get this done” after a rare Capitol Hill visit to lobby lawmakers.

Nancy Pelosi, the Democratic Speaker of the House of Representatives, was due to bring the US president’s $1.2tn infrastructure legislation to a vote this week but has repeatedly pushed back a self-imposed deadline amid a party split over whether to link its passage to a separate $3.5tn spending bill backed by progressives.

After a 45-minute closed-door meeting with Pelosi and House Democrats on Friday, Biden appeared to lift deadline pressures, rejecting any suggestion of a timeline.

“It doesn’t matter when. It doesn’t matter whether it’s in six minutes, six days or six weeks,” Biden said as he left the Capitol. “We’re going to get it done.”

Pelosi had promised moderate Democrats a vote on the bipartisan infrastructure bill on Monday, and then again on Thursday, but postponed the make-or-break vote after several days of crunch talks with members of her own party.

White House officials including Ron Klain, the chief of staff, Brian Deese, the National Economic Council director, and Susan Rice, the domestic policy adviser, were closely involved in the talks as well.

Biden has this week participated in the negotiation behind the scenes. But the trip to Capitol Hill on Friday highlighted a shift in tactics by the president towards more public interventions.

Jen Psaki, White House press secretary, said Biden would also travel outside Washington next week to make the case for his plans, which the administration believes has widespread support among voters.

“[Biden] wants to speak directly to members, answer their questions and make the case for why we should all work together to give the American people more breathing room,” Psaki said just before the president’s Capitol Hill meeting. “Compromise is necessary, it’s inevitable.”

Lawmakers from Biden’s party are split over the two pillars of the president’s sweeping legislative agenda: the $1.2tn infrastructure bill and a $3.5tn spending package to improve America’s social safety net, which is opposed by Republicans and will need to pass both chambers of congress with Democratic votes alone.

Biden has staked his presidency on both measures being signed into law. Democrats in Washington are already fretting that a failure to pass either piece of legislation could hurt the president’s party in a governor’s race in Virginia next month, as well as next year’s midterm elections, when control of both chambers of Congress will be up for grabs.

“If we can get something done here, we’re going to have a historic piece of legislation passed [in] Congress. It’s going to have a huge impact on the American people and that’s one of the reasons the president wanted to go down there today,” Psaki said.

Progressive Democrats in the House have said they will not sign on to the infrastructure bill — which would invest federal funds largely in roads, bridges and tunnels, as well as broadband — until they receive assurances that the bigger bill will not be watered down in the Senate.

But those assurances seemed far off on Thursday night given the objections of Joe Manchin and Kyrsten Sinema, two of the most conservative Democratic senators. Both wield outsized power in an upper chamber of Congress divided 50-50 between Democrats and Republicans, with vice-president Kamala Harris able to cast a tiebreaking vote.

Manchin, who represents West Virginia, revealed on Thursday that he was unwilling to support a budget bill with a price tag of more than $1.5tn, while a Sinema spokesperson said the senator from Arizona also objected to the cost of the $3.5tn bill.

White House aides met Manchin and Sinema for late-night talks at the Capitol on Thursday. But Sinema’s office said on Friday that the senator had returned to Phoenix, adding she remained involved in “remote” negotiations with the White House.

Hakeem Jeffries, a member of Pelosi’s leadership team, told reporters on Friday that he expected the vote to be held — and for the bill to pass — “today”.

But others remained sceptical. Pramila Jayapal, the Democratic congresswoman who chairs the House progressive caucus, told reporters on Friday morning that her position was unchanged: she would not support the infrastructure package until a budget bill was passed.

The internal party divisions over Biden’s legislative agenda come as the Democratic party also confronts a looming crisis over the debt ceiling. Democratic and Republican lawmakers in the Senate remain locked in a stare-down over lifting the borrowing limit, with Republicans refusing to sign on to raising the debt ceiling and Democrats arguing that using a complex legislative manoeuvre known as reconciliation to do so unilaterally would be too risky.

Janet Yellen, the US Treasury secretary, has warned that the government risks default by October 18 if the borrowing limit is not lifted. Investors showed signs of nervousness about a possible default for the first time on Friday, dumping short-term Treasury bills that mature in the coming weeks.