President Obama placed calls to House Speaker John A. Boehner (R-Ohio) and Senate Majority Leader Harry M. Reid (D-Nev.) on Saturday, a sign that the president is stepping up his personal involvement in negotiations over keeping the federal government funded.

Obama’s participation in the budget talks – which he had previously delegated to Vice President Biden and Office of Management and Budget Director Jacob J. Lew — came six days from the deadline by which Congress must pass a budget measure to avoid a government shutdown.

According to a statement from the White House, Obama “made clear that we all understand the need to cut spending, and highlighted the progress that has been made to agree to all work off the same number — $73 billion in spending cuts in this year alone.”

The $73 billion figure stated by the White House is relative to Obama’s fiscal year 2011 budget, which was never enacted; in actuality, the $73 billion would represent cuts of more than $30 billion from current spending levels.

Republicans have disputed the idea that the parties are nearing agreement on a spending figure, and Boehner spokesman Michael Steel noted Saturday that on the call, “the speaker reminded the president that there is no ‘deal’ or agreement on a final number, and he will continue to push for the largest possible spending cuts.”

Jon Summers, a spokesman for Reid, confirmed that negotiations would continue throughout the weekend.

“We’re hopeful Republicans will work with us on responsible cuts that won’t harm our fragile economic recovery,” Summers said.

The White House said in its statement that Obama “has instructed his team to continue to work hard over the weekend with the appropriators to help reach resolution on the composition of those cuts, and reiterated our opposition to cuts that will undermine our economic growth, job creation, and our ability to win the future.”

“He also made clear that we continue to oppose efforts to use this process to further an ideological agenda on issues that have nothing at all to do with reducing spending or reducing the deficit,” the White House statement said, a reference to the scores of controversial policy “riders” that were tacked onto the House-passed spending bill in February. “The President highlighted the progress that has been made but made clear that this process is running short on time, and he urged both sides to reach a final solution and avoid a government shutdown that would be harmful to our economic recovery.”

GOP sources said that rather than bringing about a major breakthrough in the talks, Obama’s call to Boehner on Saturday kept things where they stood.

Even so, that Obama personally weighed in shows the significance of the moment — six days until a shutdown — because over the past month or so, as Obama has dealt with global crises such as the uprisings in Egypt and the U.S. military involvement in Libya, he has left the brunt of the budget negotiating work to Biden and Lew.

Biden last visited Capitol Hill on Wednesday night to meet with Senate Democratic leaders on the ongoing budget talks. He told reporters after the meeting that all sides are “working off the same number now,” an estimated $33 billion in cuts, although Boehner and other Republicans have disputed that agreement on such a number has been reached.

Boehner, meanwhile, has been facing pressure from his right flank on the budget negotiations; on Thursday, a couple of hundred tea party activists converged on the Capitol for a rally with conservative lawmakers including Reps. Michele Bachmann (R-Minn.) and Mike Pence (R-Ind.) to urge leaders to push for the full $61 billion in cuts passed by the House two months ago.

Faced with the possibility that they may end up losing some of their conservative members in any spending compromise, House Republican leaders have begun courting moderate Democrats on budget issues.

Congress must pass — and Obama must sign into law — a funding resolution by Friday to avert a government shutdown.

Staff writer Paul Kane contributed to this report.