By Rupert Wingfield-Hayes BBC correspondent in Beijing

The commander of US forces in the Pacific has arrived in China for the most extensive visit by a top US military leader since the collision of a US spy plane and a Chinese fighter jet a year and a half ago.

China has praised Fargo's visit

That incident plunged military relations between the two countries into a prolonged freeze, but Admiral Thomas Fargo's visit is being seen as an important sign that a thaw in military relations is now under way.

The Chinese foreign ministry spokesman said China has always been very positive towards relations between the countries' militaries.

Strained past

That is a far cry from a year and a half ago, when China accused the US military of repeatedly violating its sovereign airspace after the spy plane and fighter jet collided.

And Admiral Fargo's visit is not the only sign of growing co-operation between the two militaries.

Last week, a senior Chinese general, Xiong Guangkai, visited Washington, and last month a US warship made a port call in China.

That is not to say that the two militaries do not still have wide differences, particularly over the issue of Taiwan.

But with the US preparing for a possible war in Iraq and with North Korea's admission that it has a nuclear weapons programme, both Beijing and Washington appear to have decided they need close consultation on all levels and that includes their militaries.