The United States is considering strengthening its military forces in the Pacific Ocean as a deterrent against North Korea.

US officials said the reinforcements would help signal that a possible war with Iraq was not distracting the US from a nuclear stand-off with the North.

The USS Kitty Hawk may need to be redeployed

North Korea reacted to the reports with customary alarm, claiming the US wanted "to crush us to death".

The moves came as the UN's nuclear watchdog, the International Atomic Energy Agency (IAEA), said it would meet on 12 February to consider asking the UN Security Council to act against North Korea.

The Security Council could impose sanctions on North Korea as punishment for its nuclear programme, though the North has said such a move would amount to "an act of war".

The US wants the Security Council to handle the crisis, although Russia - a traditional ally of the North - has said it opposes the idea.

'Peaceful solution'

US Defence Department officials said one possible move was to deploy 24 additional B-52 and B-1 bombers to the island of Guam and move fighter planes to Japan.

CRISIS CHRONOLOGY

16 Oct: US announces that N Korea has acknowledged secret nuclear programme 14 Nov: Oil shipments to N Korea halted 22 Dec: N Korea removes monitoring devices at Yongbyon nuclear plant 31 Dec: UN nuclear inspectors forced to leave North Korea 10 Jan: N Korea pulls out of anti-nuclear treaty 4 Feb: US says it might reinforce troops in Pacific

Timeline of tensions

American officials denied any direct link to the confrontation with North Korea over its nuclear activities, which they said was being handled diplomatically.

The BBC Pentagon correspondent says the aim is to send a clear signal to North Korea not to take advantage of any conflict between Washington and Baghdad.

Tension between Washington and Pyongyang over North Korea's nuclear programme has been rising since October last year.

North Korea has announced its withdrawal from the Treaty on the Non-proliferation of nuclear weapons (NPT) and appears to have reactivated a controversial nuclear reactor at Yongbyon.

Analysts suspect North Korea's actions are part of hard-line negotiations to persuade the US to sign a non-agression pact and increase economic aid.

The US believes that North Korea has started moving spent nuclear fuel rods that have been in storage since 1994, presumably for reprocessing.

Analysts believe the rods contain enough raw material for six or more nuclear weapons, and that production could begin in months.

On Monday, White House spokesman Ari Fleischer said President George W Bush still believed the North Korean stand-off could be resolved peacefully.

"That doesn't mean the United States won't have contingencies and make certain those contingencies are viable," Mr Fleischer told reporters.

Pentagon officials insist that no decisions have been made. But moves reportedly being considered include:

• Giving the US aircraft carrier already based in the Pacific, the USS Kitty Hawk, a more visible presence; and replacing it with another carrier, probably the USS Carl Vinson, should the Kitty Hawk be ordered to the Gulf, as widely expected.

• Sending B-1 and B-52 bombers, and F-16 fighter jets, to the region.

• Dispatching extra intelligence, surveillance and reconnaissance units.

The United States already has 37,000 troops in South Korea, a legacy of the 1950-53 Korean War.

US Defence Secretary Donald Rumsfeld held talks on Monday in Washington with a visiting South Korean presidential envoy, Chyung Dai-chul.

A US spokesman said the 45-minute meeting had dealt with the future of US forces stationed in the South.

The envoy is also due to meet Secretary of State Colin Powell.