The top congressional leaders in both chambers have a message for the 17 appropriators making up the House-Senate conference committee on Homeland Security spending: Do your thing.

And that’s a positive sign for negotiations on border security funding that are going down to the wire again, with a Feb. 15 deadline to avert yet another partial government shutdown. Appropriators want to reach at least an agreement in principle by the end of this week, to be able to start putting pen to paper over the weekend.

Senate Appropriations Chairman Richard C. Shelby of Alabama said the target for releasing legislative text is Monday, which would enable the House to take up the measure Thursday — given that chamber’s 72-hour rule — before sending it on to the Senate, where it could need to clear a 60-vote filibuster threshold.

If they can’t make it in time, but have things close to nailed down, another short-term stopgap could be in the offing, Shelby said after a closed-door briefing with Customs and Border Protection officials Wednesday. House Appropriations ranking member Kay Granger of Texas added that she “absolutely” thinks a deal is achievable next week, if not this week.

The talks got a shot in the arm this week from each chamber’s leader, who previously had kept to each sides’ respective political talking points: Republicans backed Trump’s demand for $5.7 billion in funding for a border wall or “physical barrier,” while Democrats offered zero dollars for the wall.

House Speaker Nancy Pelosi told reporters Tuesday night after President Donald Trump’s State of the Union address and again on Wednesday that she planned to let the conferees work their will.

“Left to their own devices I think they can have an agreement on time by Friday,” the California Democrat said Wednesday. “If they have a bipartisan agreement, I will support it.” She said she communicated as much to Shelby earlier in the week, and to Vice President Mike Pence on Tuesday night.

That puts Pelosi in the same camp as Senate Majority Leader Mitch McConnell, another veteran Senate Appropriations member who for years sat across the table from Pelosi hammering out details of the annual foreign assistance budget. McConnell said Tuesday he planned to let Shelby come up with a package, and then “we’ll hope the president finds it worth signing.”

Trump didn’t give an inch in his speech Tuesday night, however, nor did CBP officials who backed up the president’s call for $5.7 billion in wall funding at the closed briefing Wednesday, according to Senate Minority Whip Richard J. Durbin. “They’re trying to rationalize the whole $5.7 billion,” the Illinois Democrat said.

Separately, House Majority Leader Steny H. Hoyer told reporters “I don’t think any of us can be confident” that Trump would sign a bipartisan package. If Trump vetoed it and all of the GOP-led Senate’s 45 Democrats and two independents stuck together on an override vote, they would need 20 of the chamber’s 53 Republicans to join them and abandon their own president.

Also watch: As lawmakers begin to hash out border security, how do conference committees work?

Middle ground possible?

But Durbin added that the unnamed officials acknowledged that cross-border drug trafficking, which runs through ports of entry that have little capacity to inspect all the vehicles coming through every day, was a major problem. Durbin asserted that when he asked the CBP officials to give lawmakers a priority list for the spending talks, “what they said was technology. They don’t rule out barriers, they don’t rule out fences, but technology was their first priority.”

Still, Durbin seemed to indicate some form of middle ground on border barrier spending was on the table. “What we need to have is clear direction on the total amount that’s being spent, what we can put into barriers and fences. Those are the two things I think are central to reaching a bipartisan agreement,” he said.

Similarly, Rep. Henry Cuellar, a Texas Democrat, said a compromise would necessarily need to cut the president’s demand down to size. “I think that there is a path forward but people need to understand we are not going to do the $5.7 billion,” Cuellar said. “$5.7 billion for a wall, no way. Can we add technology, can we add modernization of ports, can we add personnel? … I think we all agree that it has to be a comprehensive thing.”

Under the discretionary spending caps for fiscal 2019, assuming the other six outstanding appropriations bills don’t change substantively, the conference committee has roughly $49 billion to spend. Senate Republicans, in an earlier proposal, beefed up that figure to about $55 billion, mainly through the use of emergency funding for the wall and other Trump demands to get around the spending caps.

Another Democratic conferee, Rep. Pete Aguilar of California, suggested conferees have been instructed to live within the existing spending caps, which limits their options to grow CBP’s budget. The DHS bill also funds agencies such as the Transportation Security Administration, Coast Guard and Immigration and Customs Enforcement.

“In order to fund certain priorities and stay within the caps, you’re got to pull money from other areas,” Aguilar said. “So we’re trying to stay within the caps. That means we’ve got to be mindful of all the moving parts.”

One of those moving parts, of course, is Trump himself. And the president’s reaction to whatever compromise emerges from the Appropriations committees remains the great unknown, on both sides of the aisle and perhaps among Trump’s close advisers as well.

“I’m optimistic about what the appropriators are doing,” Pelosi said late Tuesday. “I do know that left to their own devices, they weigh their equities, they understand the resources that are available, the differences that we have and they can come up with a path. And the only problem is that [Trump] would stand in the way of that path.”

David Lerman, Niels Lesniewski, Kellie Mejdrich, Jennifer Shutt and Katherine Tully-McManus contributed to this report.