China's President Hu Jintao on Thursday wrapped up a visit to Russia that has seen the two powers vow to beat the economic crisis and reverse plummeting trade by bolstering their strong ties.

After the talks Wednesday with President Dmitry Medvedev and Prime Minister Vladimir Putin, the Chinese delegation met with Russian business leaders before heading to Slovakia on a two-day visit.

The leaders have been keen to play up the importance of gas and oil from Russia to energy-hungry China, including a loan deal worth 25 billion dollars for Russian oil supplies over the next 20 years through a new pipeline.

"We have started a complex cooperation in the oil sphere and reached an important breakthrough in the energy sphere," Hu said.

This deal alone means China surpassed Germany and the Netherlands as Russia's biggest trading partner in the first quarter of 2009 but volumes have fallen sharply, according to Kremlin figures.

China's economic growth, which now far outpaces that of Russia, is another trend that will increasingly weigh heavily on the two countries' relations, said Sergei Lusyanin, an expert with Moscow's Institute of Far Eastern Studies.

"The weak link in their relations is the imbalance between Russian and Chinese trade. Russia exports raw commodities while China exports machinery and manufactured products," he said.

Medvedev, however, cited bilateral trade with China worth more than 55 billion dollars in 2008, making no mention of the gloomier outlook for 2009.

Russia remains the main supplier of arms to China since the two countries normalised their relations in 1989 -- the same year that Washington imposed an arms ban on Beijing -- though those sales have slowed in the last five years.

But even as the two giants hailed their growing energy relations, trade in the sector is evolving only slowly, after the first talks on oil and gas cooperation were initiated in the 1990s.

Russian energy monopoly Gazprom said Wednesday a planned gas pipeline to China had been delayed until after 2011 after Beijing and Moscow were unable to agree on a price for the gas contract.

"This experience can be used in spheres other than the energy sector," Medvedev said. Hu added: "In the midst of the global financial crisis, we are actively developing a practical cooperation in every sphere."

The warming relations are a marked change from the Cold War era when the Soviet Union and China clashed for supremacy in the Communist world.

Both countries have taken great strides to put old rivalries behind them, ending just last year a decades-long dispute over their 4,300-kilometre (2,700-mile) border after a preliminary accord reached in 2004.

The joint declaration issued by Hu and Medvedev after their talks emphasised the two powers' shared view on many issues, including a call to increase the voice of emerging economies on the world financial stage.

The two countries' stances on how to battle the financial crisis are "close or matching," the joint statement said.

China and Russia also agreed to boost the use of their domestic currencies in bilateral trade -- a move which could lessen the dominance of the US dollar.

"The financial crisis is pushing the two countries toward new decisions, such as the plan to switch to their national currencies for bilateral projects," Lusyanin said.