WASHINGTON — Congressional negotiators on Tuesday inched toward a potential agreement on a catchall spending bill that would deny President Donald Trump’s request for immediate funding to construct a wall along the Mexico border. The emerging measure would increase the defense budget and eliminate the threat of a government shutdown on Trump’s 100th day in office this Saturday.

Top Senate Democrat Chuck Schumer said Republican negotiators were following the lead of Trump, who signaled Monday evening that he would not insist on $1 billion worth of wall funding now as an addition to the $1 trillion-plus spending bill. Trump told a gathering of conservative media reporters that he might be willing to wait until September for the funding.

A remaining stumbling block is a recent threat by Trump to scuttle a portion of former President Barack Obama’s health law that helps low-income people afford insurance policies, but the decision by Trump and his GOP allies to back down on the wall steered the talks on the spending measure in a positive direction.

Senate Majority Leader Mitch McConnell, R-Ky., said he was optimistic the talks would produce “an agreement in the next few days.”

An existing temporary funding bill expires Friday at midnight and all sides anticipated that another stopgap measure would be required to buy time for the House and Senate to process the massive spending bill, which would wrap together 11 unfinished agency spending bills through September.

Trump campaigned throughout the country last year promising a wall across the entire 2,200 mile southern border, promising that Mexico would pay for it. But while the idea is a priority of Trump’s most fervent supporters, it is resolutely opposed by Democrats and even many Republicans, who see it as wasteful and who prefer other steps like new technologies and additional border agents to curb illegal immigration.

“I support additional border security funding,” said Sen. Lindsey Graham, R-S.C., a GOP critic of Trump who dined with the president Monday at the White House. “But a 2,200-mile wall, I don’t think there’s a whole lot of support for it.”