The US plans to send up to 1,000 security officials, including 500 FBI agents, to protect its athletes at the 2012 London Olympics, a media report said on Monday.
America has raised repeated concerns about security at the Olympics and wants to provide protection for its contestants and diplomats, ‘The Guardian’ reported.
US officials have reportedly sought a breakdown of the number of British police and security personnel that will be available next summer.
But the US' need for reassurance is "exasperating" British officials and anti-terrorism officials, who have privately raised concerns about the "meddling", as well as the size of the US "footprint" in Britain during the games, the daily said.
"We are not equal partners in this. They are being very demanding," said one security official.
The games organising committee has admitted that it had underestimated the number of security guards needed at the 32 sites across the country.
Originally it had thought 10,000 guards would be enough, but after a review, it now believes it will need up to 21,000.
The Joint Terrorism Analysis Centre has lowered the threat of attack to "substantial". But western intelligence agencies remain cautious.
Experts say it is possible that Al Qaeda or its affiliates may attempt to disrupt the Olympics, with members of the US team being obvious targets.
A British official said: "They (Americans) want to see everything. We are not equal partners in this. They want to be on top of everything -- building protection, counter-terrorism strategy and VIP security - everything."
The US state department has declined to comment.