The US Defence Secretary, Donald Rumsfeld, has said he is worried about the rise of left-wing leaders in Latin America.
Mr Rumsfeld said it was a concern that the Venezuelan President, Hugo Chavez, was working closely with President Fidel Castro in Cuba and the new left-wing Bolivian leader, Ero Morales.
In particular, he said he was worried about the aims of the Venezuelan leader.
Meanwhile, Mr Rumsfeld has said that Iraqis must exert greater authority over their country and also indicated that the United States will be able to make further cuts in troop numbers.
The US has about 138,000 troops in Iraq nearly three years after the start of a war which ousted Saddam Hussein.
The force has already been reduced by more than 20,000 from the roughly 160,000 in place for the constitutional referendum last October and the December elections.
US defence officials have said the Pentagon is exploring options for this year, including dropping down to about 100,000 American troops if security conditions permit and political progress continues.
Book claims prior decision on war
Downing Street and the White House have declined to comment on claims that the British Prime Minister and US President had already decided to launch a war against Iraq, while approval for military action was still being sought at the United Nations.
In a book on the build-up to the war, London-based human rights lawyer Philippe Sands says that early in 2003 Tony Blair and George W Bush considered provoking Saddam Hussein to break UN resolutions which might have justified a military response.
Professor Sands claims a memo records both men as prepared to act without a new resolution.
