Hillary Clinton will have top billing on the second night of the Democratic convention later this month in Denver, Bar4ack Obama revealed this morning.

The announcement comes as Obama tries to douse embers of resentment among Clinton's backers.

Obama's campaign called the former first lady, who nearly upended his bid for the Democratic nomination in an extended and often bitter primary season, 'a champion for working families and one of the most effective and empathetic voices in the country today'.

She will speak on Tuesday, August 26 - the 88th anniversary of U.S. women's right to vote.

Peace deal: Barack Obama greets Hillary Clinton. She will give a keynote speech on the second day of the Democratic nomination

There still was no word on whether Clinton would seek a roll call vote for her candidacy as a means of allowing her large bloc of delegates to express a "cathartic" expression of support before falling in line behind Obama.

Clinton's husband, former President Bill Clinton, who has offered only tepid support for Obama, was not listed in the campaign's news release, although it has said he would speak on the third night of the convention.

The headliner on that night, the campaign said Sunday, would be Obama's as-yet- unannounced vice presidential selection.

Obama is expected to become the party's first black presidential nominee on the fourth and final night as the convention moves from the indoor Pepsi Arena to a bigger venue at Invesco Field at Denver's Mile High stadium.

That night is the 40th anniversary of Martin Luther King's "I Have a Dream" speech.

Obama, who is on vacation visiting his grandmother in his birth state of Hawaii, and Republican opponent John McCain were taking the day off Sunday from a campaign that has grown increasingly negative.

McCain's campaign manager kept up the attack in the candidate's absence, saying on a Sunday political talk show that it was Obama, not the four-term Arizona senator, who first began negative campaigning.

McCain has tried to portray Obama as an empty celebrity who gets more than his share of media coverage.

In the sing of things: Barack Obama talks with an unidentified man carrying golf clubs as he leaves after playing golf in Hawaii at the weekend

"Obama started negative campaigning on John McCain long before we started punching back, and I think a lot of our effort is really to get back into this game, try and galvanize some of the public attention back onto this race, make sure everybody understands there's two people in this race, not just one, and I think we've been successful in doing that," Rick Davis said on Fox television without elaboration.

Earlier, the two candidates joined in condemnation of Russian attack on neighboring Georgia, the first major U.S. foreign policy crisis of the general election campaign.

McCain warned the Kremlin of long-term consequences and Obama called for immediate mediation.

Russia, nevertheless, expanded its bombing blitz Sunday and early Monday against U.S.-allied Georgia, targeting a military airfield on the outskirts of the country's capital Tbilisi.

The attack was launched even though Georgia said it had pulled out of the breakaway province of South Ossetia, as Moscow has demanded.

Georgia has been riven by strife brought on by the breakaway sentiments of two regions inside its borders - Abkhazia and South Ossetia - since the former Soviet republic gained independence from Moscow in the early 1990s.

Both regions have found backing from the Russians, who have sent troops to the region to act as peacekeepers.

McCain has routinely sought to play on his long association with international and security affairs against Obama's short record on the national stage.

On Iraq, the other key foreign affairs issue facing voters this year, McCain has portrayed Obama as focused more on his own ambition than military success in Iraq.

Obama argued that McCain favors extending a war that is hurting Americans at home.

In Baghdad, meanwhile, Foreign Minister Hoshyar Zebari yesterday said Iraqi negotiators were "on the brink" of reaching a long-term security pact with the United States that will decide the fate of American troops in Iraq.

Zebari said the Iraqis are insisting on the inclusion of a "clear timeline" for the withdrawal of U.S.-led forces.

But he has refused to give any dates. American acceptance - even tentatively - of a specific timeline would represent a dramatic reversal of American policy in place since the war began in March 2003.

McCain has vowed to keep U.S. forces in Iraq as long as "conditions on the ground" require their presence. Obama and Iraqi Prime Minister Nouri al-Maliki say American troops should be out of the country in 2010.