WASHINGTON — The Pentagon's top military officer said Wednesday that he expects to be able to recommend further troop reductions in Iraq this fall.

Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, said that on his recent trip to Iraq, he found conditions had improved more than he expected.

"I won't go so far as to say that progress in Iraq from a military perspective has reached a tipping point or is irreversible — it has not, and it is not," Mullen told a Pentagon press conference.

"But security is unquestionably and remarkably better. Indeed, if these trends continue I expect to be able early this fall to recommend to the secretary and the president further troop reductions," he said.

His remarks came in the midst of an election year in which Sens. John McCain and Barack Obama, the Republican and Democratic presidential nominees-in-waiting, have disagreed over U.S. strategy in Iraq with the war now in its fifth year.

The military surge there that began more than 18 months ago has ended. In recent days, the 3rd Infantry Division's 2nd Brigade, the last of the five additional combat brigades sent in by President Bush last year, left the country.

Its departure marks the end of what the Pentagon calls the "surge." And it starts the 45-day evaluation period that Gen. David Petraeus, the top U.S. commander in Iraq, told Congress he would need to assess the security situation and determine how many more troops he could send home.

Commanders have talked carefully, but somewhat optimistically, about the prospects for cutting troop levels more later this fall.

In recent months, they have pointed to two significant improvements: Violence is down, and the Iraqi forces are rapidly growing in size and ability.

Officials have been hoping that if security continues to improve in Iraq, they may be able to send more units to Afghanistan, where they say violence is increasing because of the flow of militants from neighboring Pakistan.

Defense Secretary Robert Gates said Wednesday that officials are looking for ways to send additional U.S. troops to Afghanistan this year.

For his part, Petraeus remains mum. When questioned by lawmakers in May, he would say only that he is likely to recommend more troop cuts in the fall.

"I do believe there will be certain assets that, as we are already looking at the picture right now, we'll be able to recommend can be either redeployed or not deployed to the theater in the fall," he said.