The United States moved closer to a default that could damage the economy, and a partial government shutdown entered its 14th day Monday, as Democratic and Republican leaders in the Senate remained at odds in their last-ditch negotiations to end the fiscal crises gripping Washington.

Congress is racing against the clock, with Treasury Secretary Jack Lew warning that the U.S. will quickly exhaust its ability to pay its bills on Thursday. Christine Lagarde, the International Monetary Fund's managing director, spoke fearfully about the disruption and uncertainty, warning on Sunday of a "risk of tipping, yet again, into recession" after the fitful recovery from 2008.

The reaction of world markets and the Dow Jones on Monday could provide the necessary jolt to Senate leaders, who represent the last, best chance for a resolution after talks between President Barack Obama and Republican leaders of the House of Representatives collapsed. U.S. futures were down sharply Monday, with light trading as expected on a holiday. Earlier, trading in Asia was muted, with markets in Tokyo and Hong Kong closed for holidays.

At issue are two normally routine pieces of legislation that have become entangled in disputes over Obama's health-care overhaul, the Affordable Care Act (ACA), and overall government spending. Congress' failure to pass a bill temporarily funding the government led to the partial shutdown on Oct. 1, the first in 17 years. And if Congress does not approve a separate measure increasing the debt ceiling — the amount of money the federal government is allowed to borrow — the Obama administration says it will not be able to pay its bills, risking default.

Obama and Vice President Joe Biden are scheduled to meet with the two chambers' leaders from both parties on Monday to discuss possible solutions for the stalemate.

