The US federal government moved toward a partial shutdown on Wednesday after Congress failed to agree on a stopgap spending measure, forcing agencies to begin furlough preparations. Lawmakers returned to Washington this week facing what House leaders called a narrowing window to avert a lapse.

The House of Representatives reconvened Monday with the funding fight at the top of its agenda, according to schedules published by the Speaker's office. Republican leaders and Democratic appropriators remained divided over spending levels and policy riders, leaving no clear path to a deal before the deadline.

The standoff came as President Donald Trump escalated tensions with Iran, adding foreign-policy strains to an already crowded legislative calendar. Democratic leaders in the Senate, including Minority Leader Chuck Schumer, blamed Republicans for refusing to negotiate on health-care and domestic spending provisions.

A lapse in appropriations would furlough hundreds of thousands of federal employees and suspend non-essential services, according to guidance from the Office of Management and Budget. Agencies including the Interior Department and the Internal Revenue Service circulated contingency plans to staff in recent days.

The Speaker of the House and Senate leaders signaled that short negotiating sessions would continue through the week in an effort to limit the shutdown's duration. Both parties braced for a prolonged blame contest heading into the autumn.