With or without a formal title, Colin Powell will have Barack Obama’s ear if the Democratic presidential candidate wins the White House in the Nov. 4 election, the candidate said Monday.

“He will have a role as one of my advisers,” Barack Obama said on NBC’s “Today” in an interview aired Monday, a day after Powell, a four-star general and President Bush’s former secretary of state, endorsed him.

“Whether he wants to take a formal role, whether that’s a good fit for him, is something we’d have to discuss,” Obama said.

Being a top presidential adviser, especially on foreign policy, would be familiar ground to Powell on a subject that’s relatively new to the freshman Illinois senator. Obama has struggled to establish his foreign policy credentials against GOP candidate John McCain, a decorated military veteran, Vietnam prisoner of war and ranking Republican on the Senate Armed Services Committee.

In the NBC interview, Obama said Powell did not give him a heads-up before he crossed party lines and endorsed the Democratic presidential candidate on the network’s “Meet the Press” a day earlier.

In that interview, Powell called Obama a “transformational figure” in the nation’s history and expressed disappointment in some of McCain’s campaign tactics. But, Powell said, he didn’t plan to hit the campaign trail with Obama before Election Day.

“I won’t lie to you, I would love to have him at any stop,” Obama said with a grin Monday. “Obviously, if he wants to show up, he’s got an open invitation.”

Powell’s endorsement came just hours after Obama’s campaign disclosed that it raised $150 million in September — obliterating the old record of $66 million it had set only one month earlier.

White House spokeswoman Dana Perino said she had not spoken to Bush about his reaction to Powell’s endorsement but added that Bush and Powell have a good relationship.

“The president greatly respects Gen. Powell as we all do,” Perino told reporters aboard Air Force One en route to an event in Louisiana.

Powell expressed disappointment in the negative tone of McCain’s campaign, his choice of Alaska Gov. Sarah Palin as a running mate and their decision to focus in the closing weeks of the contest on Obama’s ties to 1960s-era radical William Ayers, saying “it goes too far.”

McCain, meanwhile, seemed dismissive of Powell’s endorsement, saying it wasn’t a surprise, that the two share mutual respect and are longtime friends.

The Republican from Arizona pointed out on Sunday that he had support from four other former secretaries of state, all veterans of Republican administrations: Henry Kissinger, James A. Baker III, Lawrence Eagleburger and Alexander Haig.

At a boisterous rally Sunday, Obama said McCain was “out of ideas and almost out of time.”

He and his aides appear so confident of his prospects that apart from a brief stop in Madison, Wis., next Thursday, Obama currently has no plans during the next 10 days to return to Pennsylvania, Minnesota, New Hampshire or any other state that voted for John Kerry in 2004.

Instead, he intends to spend two days this week in Florida, where early voting begins on Monday, and travel to Virginia, Iowa, Ohio, Colorado, New Mexico and possibly Nevada and Indiana. Those states hold 97 electoral votes combined, and Bush won all in 2004.

Obama also may stop in West Virginia, where his campaign recently bought statewide television advertising in a late attempt to put the state’s five electoral votes into serious contention.