WASHINGTON (AP) — The Senate's top leaders announced Wednesday they have sealed agreement on a two-year budget pact that would shower both the Pentagon and domestic programs with almost $300 billion above existing limits, giving wins to both GOP defense hawks and Democrats seeking billions for infrastructure projects and combatting opioid abuse.

The agreement is likely to be added to a stopgap spending bill that passed the House on Tuesday and is aimed at averting a government shutdown Thursday at midnight.

The plan also contains almost $90 billion in overdue disaster aid for hurricane-slammed Texas, Florida and Puerto Rico.

And it would increase the government's borrowing cap to prevent a first-ever default on U.S. obligations that looms in just a few weeks.

The House's top Democrat, however, swung out against the plan.

House Minority Leader Nancy Pelosi of California announced she would oppose the budget measure unless her chamber's GOP leaders promised a vote on legislation to protect "Dreamer" immigrants who face deportation after being brought to the U.S. illegally as children.

The House on Tuesday passed legislation to keep the government running through March 23, marrying the stopgap spending measure with a $659 billion Pentagon spending plan, but the Senate plan would rewrite that measure.

Senate Democratic leaders have dropped their strategy of using the funding fight to extract concessions on immigration, specifically on seeking extended protections for the "Dreamer" immigrants. Instead, Senate Minority Leader Chuck Schumer, D-N.Y., went with a deal that would reap tens of billions of dollars for other priorities — including combatting opioids — while hoping to solve the immigration impasse later.

The budget agreement would give both the Pentagon and domestic agencies relief from a budget freeze that lawmakers say threatens military readiness and training as well as domestic priorities such as combating opioid abuse and repairing the troubled health care system for veterans.