WASHINGTON - US Senate on Thursday approved the postponement of the federal government's debt ceiling until May to keep the federal government in operation and give lawmakers more time to mull over how to rein in the government's mounting deficit.

The 64-34 vote in the Democratic-led Senate sent the bill to US President Barack Obama to sign into law. The White House has said Obama would sign it.

The bill, which cleared the House last week, would temporarily suspend the 16.4-trillion-dollar debt ceiling until May 19, allowing US Treasury Department to borrow whatever sum is necessary to pay the government's bills before that date.

The measure, initiated by the House Republicans, will temporarily defuse the looming default crisis, and at the same time set a timeline for the next phase of budget wrangling.

The House Republicans backed down from their previous demand that any debt ceiling increase be paired with comparable spending cuts. They shifted from default threat in order to force the Senate to pass a budget to cut government spending.

Pressure now increases on the Senate that has not produced a budget plan for the federal government since 2009. The bill requires each chamber of Congress to pass a budget resolution by April 15 or have lawmakers' salaries withheld, the "no budget, no pay" provision.