Russia and China stress the basic importance of the ABM treaty, which is a cornerstone of strategic stability and the basis for reducing offensive weapons

Joint statement

They issued a separate declaration stressing their commitment to the 1972 Anti Ballistic Missile (ABM) Treaty, which the US wants to redraw as part of its missile project.

The statement calls the treaty a "cornerstone of strategic stability and the basis for reducing offensive weapons", reported Russian news agency Tass.

The friendship pact itself contains no military or political alliances, focusing instead on boosting the two countries' mutual interests and boosting trade.

The BBC's Adam Brooks says trade between the countries is only a tiny part of their economic interests, but the developing relationship between Moscow and Beijing will be watched more for its strategic importance.

Russia and China have found common ground in their opposition to Washington's "Son of Star Wars" anti-missile programme, which had its latest test at the weekend.

The US successfully tested its missile at the weekend

China and Russia say they are not planning any kind of military or political bloc and that their friendship treaty, intended to replace a 1949 Communist-era pact, does not threaten anyone.

They reject suggestions that they are forming an anti-American alliance.

'Dangerous step'

But they are united by their opposition to US defence strategy.

"It is not favourable to global strategic balance and stability," a foreign ministry spokesman in Beijing said following the weekend tests.

China is vehemently opposed to the US plans for a missile defence system because of the threat it will pose to its own tiny second-strike capability.

And Russia also released a statement saying the test threatened the international structure of nuclear disarmament.

"A logical question again arises - why take matters to the point of placing under threat the entire internationally agreed structure of nuclear disarmament and non-proliferation, including its core, the 1972 ABM treaty?" Russian foreign ministry spokesman Alexander Yakovenko said in a statement.

Pentagon officials promised to press forward with plans for more tests of the system after an interceptor missile hit a dummy warhead over the Pacific Ocean on Saturday.

Russian officials have said President Putin will take up concerns over the project with US President George W Bush at the forthcoming G8 summit in Genoa.

Trade boost

Under the terms of the friendship pacts, the two countries aim to boost bilateral trade, which is expected to rise this year to $10bn from last year's $8bn. But the total is - still far short of Beijing's annual trade with Japan or the United States.

Some analysts say the treaty was pushed by both sides as a defensive measure as it bonds two countries that in many respects are potential adversaries.

Russia fears the weight of China's population bearing down on its far east, while China sees a revitalised Russia as a possible rival for influence in Asia.