UPDATE 2-Top U.S. Senate Democrat, Republican confident on debt-ceiling hike

(Adds McConnell comments)

By Moira Warburton

WASHINGTON, Nov 30 (Reuters) - The top Democrat and the top Republican in the U.S. Senate voiced confidence on Tuesday that they would pass legislation raising the federal government's $28.9 trillion debt limit soon, averting a catastrophic default.

Senate Majority Leader Chuck Schumer said he expects to pass the increase "soon," after a "good conversation" with Senate Minority Leader Mitch McConnell.

"The Senate must take action to make sure the United States does not default on its sovereign debt for the first time in its history," Schumer said on the Senate floor on Tuesday.

"I recently had a good conversation with the Republican leader about this issue and expect to continue those talks... I look forward to achieving a bipartisan solution to addressing the debt limit soon."

McConnell also appeared to be optimistic, declaring to reporters later in the day that the federal government would not default on its debt. He described his talks with Schumer as "useful" and added that he was also confident Congress would avoid a partial government shutdown this week.

"Certainly, nobody needs to be concerned about a government shutdown," McConnell told a news conference.

Neither said when they expected a vote on the debt limit to be held on the Senate floor.

But Dick Durbin, the No. 2 Senate Democrat, noted that Schumer and McConnell discussed the debt limit and other pending issues last week. "It is a rare moment when you say Chuck and Mitch met and they talked about something," he said. "I hope it's positive."

The non-partisan Congressional Budget Office on Tuesday said that without a prompt increase in the Treasury Department's borrowing authority, it could run out of cash before the end of December if it transfers, as planned, $118 billion to the Highway Trust Fund on Dec. 15. (Reporting by Moira Warburton, Richard Cowan and David Morgan; Editing by Scott Malone and Andrea Ricci)