He told reporters he chose an experienced national security team because 'I'm a strong believer in strong personalities and strong opinions'. But at the same time, he said he will follow the model of former president Harry Truman and that 'the buck will stop with me'.

He said of Mrs Clinton, his Secretary of State: 'She's an American of tremendous stature who will have my complete confidence, who knows many of the world's leaders, who will command respect in every capital, and who will clearly have the ability to advance our interests around the world.

'Hillary's appointment is a sign to friend and foe of the seriousness of my commitment to renew American diplomacy and restore our alliances.'

He also chose retired Marine General David Jones to be National Security Adviser and adviser Susan Rice to be US ambassador to the United Nations.

Arizona Governor Janet Napolitano will be Homeland Security Secretary and Mr Eric Holder, Attorney-General.

Mr Holder, a 57-year-old veteran lawyer with a reputation for fighting corruption, if confirmed by the US Senate, would become the United States' first black chief of the Justice Department.

In roping Mrs Clinton, Gen Jones and Mr Gates - who will stay on as Defence Secretary - into his new national security team, Mr Obama has chosen three people who have differed with each other - and with him - on the full menu of security issues, including Iraq, Iran, Afghanistan, nuclear weapons and the Arab-Israeli conflict.

Their collaboration is not likely to be as contentious as the first-term Bush administration battles among former defence secretary Donald Rumsfeld, former secretary of state Colin Powell, and Vice-President Dick Cheney.

But Mr Obama will have some clear choices among their views, which differ in nuance in some cases and more starkly in others.

He appears determined to keep them in line; advisers say he believes the Pentagon has become too strong and wants to reassert White House control.

Some American supporters of Israel have been buzzing over the potential for conflict between Mrs Clinton and Gen Jones on Arab-Israeli issues.

Gen Jones was appointed in November last year as a Bush administration envoy tasked with trying to improve often dysfunctional Palestinian security forces.

He drafted a report that criticised the Israeli Defence Forces' activities in the Palestinian territories, and also reportedly favoured the temporary deployment of a Nato-led international force there.

Mrs Clinton is viewed as holding centre-right views on Israeli security issues.

Gen Jones has separated himself from Mr Obama on a few issues. Last year, he warned that setting an arbitrary deadline for removing US troops from Iraq would be 'against our national interest'. But he agreed with Mr Obama that the focus on Iraq has distracted from a needed emphasis on Afghanistan.

Mr Gates has indicated significant differences with Mr Obama and Mrs Clinton. He is a believer in missile defence, while experts believe the new administration will slow the deployment of a proposed system in the Czech Republic and Poland to ease tensions with Russia.

ASSOCIATED PRESS, LOS ANGELES TIMES, AGENCE FRANCE-PRESSE