WASHINGTON - President Joe Biden will continue talks with congressional leaders on the United States' debt limit later this week, the White House said on Wednesday, as U.S. House Speaker Kevin McCarthy vowed to avoid a default.

"I think at the end of the day, we do not have a debt default," McCarthy said in an interview with CNBC.

"The thing I'm confident about is now we have a structure to find a way to come to a conclusion. The timeline is very tight. But we're going to make sure we're in the room and get this done," he added.

The comments come after the Democratic president and the House's top Republican met for about an hour at the White House on Tuesday with Senate Majority Leader Chuck Schumer, Senate Republican leader Mitch McConnell and House Democratic leader Hakeem Jeffries.

Financial markets appeared to be buoyed by the discussions as McCarthy joined McConnell and the White House in pledging that the United States would not fail to pay its debt obligations.

U.S. stock indexes were set to open higher on Wednesday amid cautious optimism among investors. The U.S. Treasury has said it could start running out of funds as early as June 1 to pay the government's bills -- a move economists fear the country will trigger a recession.

Biden will speak with top lawmakers by telephone while attending the Group of Seven summit of world leaders in Japan, and will meet with top lawmakers again when he returns, White House spokeswoman Karine Jean-Pierre said in television interviews.

"He's optimistic that we'll get to a reasonable, bipartisan budget deal that can get to his desk next week that he can sign," Jean-Pierre told CNN, adding that daily staff-level talks are expected to continue this week.

After Tuesday's meeting, McConnell told reporters: "We know we're not going to default." Biden also called the discussion productive.

Jean-Pierre, too, stood by the White House's stance that the country would not default, telling CNN that Biden's decision to cut short his Asia trip to return to Washington sends "the other message too, is that ... America does not default on its debt."

WORK REQUIREMENTS

Negotiations are continuing over the longevity of any deal, work requirements for key food and aid programs, and spending caps.

Asked on CNN if Biden wanted the debt limit agreement to last through 2025, Jean-Pierre declined to answer.

She also did not give details on negotiations over expanding work requirements for the two programs that provide food and cash aid to low-income families, which Republicans want to see included as part of a deal.

"The Republican proposals - they want to cut healthcare, they want to increase poverty, and it's not going to save much money," she told CNN, adding that daily staff talks between both sides were expected to continue.

House Democratic leader Jeffries said it was "unreasonable" to include work requirements in any deal to pay debts the nation has already incurred but that they could be discussed as part of other legislation.

"I'm optimistic that common ground can be found in the next week or so," Jeffries said on CNBC.

McCarthy, whose fellow Republicans control the House, on CNBC defended conservatives' call for work requirements, saying they would help the economy and boost the workforce, and vowed to exclude any discussion of taxes.

Raising taxes on the wealthy and companies to help pay for programs for other Americans is a key part of Biden's 2024 budget, and Biden on Tuesday said he was disappointed that Republicans will not consider ways to raise revenue.

(Reporting by Susan Heavey and Doina Chiacu; Editing by Andrew Heavens and Jonathan Oatis)