Washington ? President Bush’s new chief of staff said Monday it was time to “refresh and re-energize the team,” and he told senior White House aides who might be thinking about quitting this year to go ahead and leave now.

Taking charge in a time of crisis, with Bush’s poll ratings at their lowest point ever and Republicans anxious about the November elections, Joshua Bolten laid down his pointed directive at his first meeting with top presidential aides.

He did not ask for anyone’s resignation, and none of the senior aides stepped forward to say they would go, White House press secretary Scott McClellan reported later. But Bolten has Bush’s full authority to make changes to the president’s staff, and McClellan said he would expect announcements soon.

One of the first jobs to be filled is that of budget director – the position Bolten left to become chief of staff. The job of domestic policy adviser at the White House is open as well. Bolten gave top aides the option of leaving first.

“He wanted to make sure he had the team in place that is going to be here for a minimum of the remainder of the year,” McClellan said. “And he said if people are thinking about leaving, that now is the time to come to such a decision.”

Bolten told the staff he was assuming his new job at a challenging time when the United States was engaged in a war on terrorism. As U.S. casualties rise in Iraq, Bush faces sagging public support, Republican angst about the midterm election and struggles with a Congress resistant to some of his top priorities.

“Josh talked about how this is a time to refresh and re-energize the team and for all of us to renew our commitment as we go forward,” McClellan said. Republicans outside the White House say they expect changes in Bush’s lobbying staff and perhaps in the communications office, as well as in the Cabinet.

McClellan said Bolten’s invitation was specifically for the White House staff, but the president would “be looking to Josh for his advice and counsel” when it comes to possible changes in the broader administration.

To quell speculation about Donald Rumsfeld, Bush issued a strong statement of support for the embattled Pentagon chief last Friday.

On Monday, Bolten was on hand as Bush toured Europa Stone Distributors in Sterling, Va., to promote his tax plans with another Cabinet member who is the focus of shake-up rumors – Treasury Secretary John Snow. Bush did not say anything publicly about Snow’s future.

Bolten already has had closed door meetings with some top presidential advisers and plans more, McClellan said.

“There are a number of people that have served this president for a long period of time, and so you have to balance change with continuity,” McClellan said.

Bolten also was examining the numerous meetings that consume hours of staff time at the White House. Staffers often complain that they are tied up in meetings throughout the day that keep them from doing other work.

Bolten is only Bush’s second chief of staff. Andy Card left Friday after serving Bush for more than five years.

McClellan would not comment on his own future at the White House.

“I never speculate about personnel measures,” McClellan said, with a smile.