WASHINGTON — John McCain's comments yesterday seeming to downplay the return of U.S. troops from Iraq set off another presidential campaign fight over the war.

When asked by Matt Lauer, host of NBC's "Today," whether he had an estimate for when troops would start returning home, McCain said, "No, but that's not too important. What's important is the casualties in Iraq."

Supporters of presumptive Democratic nominee Barack Obama immediately assailed McCain, calling him, in the words of Sen. John Kerry, "unbelievably out of touch."

In a quickly arranged conference call, McCain supporters answered back, saying the Republican candidate was referring to an estimate of when troops could come home and that his main goal is eliminating U.S. deaths in the war that has lasted more than five years.

Yesterday's flurry was another in a series of Democratic attacks aimed at portraying McCain as committed to an open-ended U.S. presence in Iraq. Obama and other Democrats, such as party Chairman Howard Dean, have criticized McCain for an earlier comment suggesting that the U.S. commitment in Iraq could last up to 100 years.

Obama foreign policy adviser Susan Rice also noted that in weeks past McCain has confused Sunnis and Shiites, and misstated the current troop level in Iraq.

The charges and countercharges also showed the shifting nature of this year's presidential campaign. A previous Democratic vice presidential nominee defended Republican McCain, who was attacked by the former Democratic presidential nominee who asked McCain to run with him.

Sen. Joe Lieberman of Connecticut, who calls himself an independent Democrat, accused the Obama campaign of a "partisan attempt to distort John McCain's words" after the campaign organized a conference call during which Kerry, the 2004 Democratic presidential nominee, criticized McCain. Kerry had asked McCain to be his running mate, but McCain declined.

Lieberman, the 2000 Democratic nominee for vice president, said his fellow Democrats are worried because McCain was right about the need last year to change strategy in Iraq and back it with 30,000 additional U.S. troops.

Although U.S. combat casualties in Iraq have declined this year, the Iraq war remains one of the campaign's main issues. The issue in Iraq, McCain said, is reducing casualties so troops can "come home with honor and victory."

McCain foreign policy adviser Randy Scheunemann said McCain's "not too important" comment referred to the question of whether he had a "better estimate" of when troops might be coming home.