WASHINGTON (CNN) -- President Bush on Tuesday emphasized once again his support for his defense secretary, saying Donald Rumsfeld "is doing a fine job."

At a Rose Garden ceremony announcing his nominees for budget director and trade representative, Bush referred to the controversy in which six retired generals recently have called for Rumsfeld's resignation.

"I hear the voices, and I read the front page and I know the speculation," the president said.

"But I'm the decider, and I decide what's best. And what's best is for Don Rumsfeld to remain as the secretary of defense."

Also Tuesday, Rumsfeld planned to meet with a group of retired generals who regularly appear as analysts on television and in newspapers.

Retired Air Force Maj. Gen. Donald Shepperd, a CNN military analyst who will attend the session, said more than a dozen similar meetings have been held in the past. But he said that Tuesday's meeting was called late last week, apparently in response to recent events.

Shepperd said such meetings give the generals an opportunity to ask tough questions and that they are not limited to those who agree with the Pentagon on every issue.

Recently, six retired generals -- including former commanders of two Army divisions that saw combat in Iraq -- have called for Rumsfeld to resign.

They accuse him of ignoring advice from senior officers about how to prosecute the war and sending too few troops into Iraq to manage the occupation after the March 2003 invasion.

In defense of Rumsfeld, four retired generals wrote an op-ed piece Monday in The Wall Street Journal suggesting that some of his critics don't understand the war on terrorism.

"Much of the acrimony expressed by Secretary Rumsfeld's military critics appears to stem from his efforts to 'transform' the military by moving to a joint expeditionary force that is lighter and more mobile in nature to meet the nation's current and future threats," the commentary said.

"Many senior officers and bureaucrats did not support his transformation goals -- preferring conventional weapons of the past ... which prove practically useless against lawless and uncivilized enemies engaged in asymmetric warfare," the writers continued.

On Monday, U.S. Rep. Harold Ford Jr., a Tennessee Democrat running for his state's Senate seat, suggested replacing Rumsfeld with former Secretary of State Colin Powell.

"Gen. Powell's experience resolving complicated and sensitive national security challenges is needed now more than ever," Ford said in a statement.

"He will bring a respect for our military, a willingness to listen, a capacity to admit and correct mistakes and an attention to detail that is absent now in the top job at the Pentagon."