The USS George Washington is set to dock on Thursday, becoming the first US nuclear-powered aircraft carrier to be stationed outside of the US.

Wearing pink and orange gloves as a symbol of unity, demonstrators marched around the US base under drizzling rain in Yokosuka, a major naval hub 50 kilometres south of Tokyo.

'We don't need a security pact with the US! We don't need the US military here!' the demonstrators shouted. 'We don't need nuclear-powered ships!'

Japan has agreed to accept the 97,000-tonne George Washington to replace the diesel-powered USS Kitty Hawk, which is being retired from service after being stationed for 10 years in Yokosuka.

The US argued that it must deploy its best carrier in Yokosuka due to East Asia's tense security situation.

The huge vessel with a 333-metre flight deck, carrying over 70 aircraft, is installed with two nuclear reactors that can power the ship for 18 years at a time.

'I'm afraid of a radiation accident or a collision' of the vessel, said Mr Takahiro Nakajima, 70, one of the Yokosuka residents participating in the demonstration. 'But I'm also concerned about crimes by US servicemen.'

'It's clear as daylight we will have more crimes if more of them come here.'

The US stations more than 40,000 troops in Japan, which has been officially pacifist since defeat in World War II. Relations have often been tense with residents accusing the soldiers of causing noise and crime.

Japan is the only nation to have suffered atomic attack and has campaigned to abolish nuclear weapons.

Fears over the USS George Washington rose when it caught fire in May, injuring dozens of sailors. -- AFP