US Democrat Barack Obama has asked three people, including Caroline Kennedy, to lead a search for a prospective vice presidential running mate.

Ms Kennedy, daughter of former President John Kennedy, will be joined by former Fannie Mae CEO Jim Johnson, who performed the same task for John Kerry in 2004 and Walter Mondale in 1984, and former deputy Attorney General Eric Holder.

Senator Obama's campaign said that he is pleased to have three talented and dedicated individuals managing this rigorous process.

Campaign officials said that he will work closely with them in the coming weeks but ultimately this will be his decision and his alone.

Earlier today, Senators Barack Obama and Hillary Clinton asserted their commitment to Israel, the day after their long and bitter Democratic presidential primary campaign ended.

Both politicians addressed the America-Israel Public Affairs Committee this afternoon, a powerful lobbying group that has generated millions of dollars for Democratic candidates.

Senator Obama, who last night won enough delegates to secure the Democratic nomination for president, asked members of the committee to ignore attack emails that have suggested he supports the Palestinian political party Hamas.

He laid out his Israel platform which includes financial assistance for the Middle East nation and its 'right to self defence'. He also said he will not let 'terrorists' sit at the negotiating table and will do everything in his power to prevent Iran from building nuclear weapons (click here to read Mr Obama's Israel Fact Sheet).

Over, but not done

While Senator Clinton won yesterday's South Dakota primary, Mr Obama received a share of the delegates he needed to put him over the top.

He also won the Montana primary.

Hillary ClintonMrs Clinton (left) is refusing to concede, hoping to take her lead in the popular vote to the superdelegates this week.

Some 70 of the previously uncommitted superdelegates pledged to support Senator Obama at the party's convention in August.

One of Senator Clinton's top supporters, Governor Ed Rendell of Pennsylvania, told CNN he expected her to spend today and Thursday making her pitch to superdelegates.

'I don't think it's going to prevail, to be candid,' he said. 'Senator Obama is going to get the delegates he needs certainly by the end of the week, then I think Senator Clinton is going to do the right thing and move fairly decisively to unify the party and we will all follow her lead.'

Meanwhile, Secretary of State Condoleezza Rice hailed Barack Obama becoming the first African-American presidential nominee of a major US party, saying it showed America was an extraordinary country.

Ms Rice said that the United States of America is an extraordinary country, a country that has overcome many, many years of trying to make good on its principles.

But Secretary Rice, who is the highest ranking black American in the current White House administration, added she wanted to stay out of the presidential campaign itself.

Her predecessor Colin Powell was the first African-American to hold the post as US secretary of state.