U.S. President Donald Trump asked Congress to claw back nearly $5 billion in already-approved foreign aid spending, a proposal timed to take advantage of the looming end of the fiscal year and allowing him to cut the funding himself if lawmakers fail to act by the close of September.

The maneuver challenges Congress’ spending powers and intensifies an already contentious battle over government funding, which is due to lapse Sept. 30. Democrats are sure to seek guarantees Trump will actually spend money lawmakers appropriate in exchange for their votes to keep the government open.

The proposed cuts include $3.2 billion in U.S. Agency for International Development assistance, $322 million from the USAID-State Department Democracy Fund, $521 million in State Department contributions to international organizations, $393 million in State Department contributions to peacekeeping activities and $445 million in separately budgeted peacekeeping aid, according to an administration official who described the notification on the condition of anonymity.