Russian President Vladimir Putin has highlighted the significance of stepping up cooperation between his country and China, adding that the two sides can resolve the current common difficulties by joining efforts.

He made the comments during a meeting with Chinese President Xi Jinping on the sidelines of the BRICS summit of emerging economies in the Russian city of Ufa on Wednesday.

BRICS is made up of Brazil, Russia, India, China and South Africa.

"We are well aware of difficulties that we have to face both in economy and international politics, but [by] combining efforts, no doubt we will overcome all the problems before us and solve all the problems and tasks before us," the Russian president said.

Putin also thanked Xi for taking part in the summits of the Shanghai Cooperation Organization (SCO) and BRICS in Russia.

"I will not hide that it is especially pleasant to see our friends from China, taking into consideration the great amount of our humanitarian and political contacts and the growing volume of trade and economic ties," Putin added.

The two-day BRICS summit started on Wednesday.

BRICS accounts for almost half the world's population and about one-fifth of global economic output. Its New Development Bank is seen on course to challenge the dominance of the US-led World Bank and International Monetary Fund.

China has turned into Russia's biggest trading partner as Moscow is looking for markets in Asia in the face of Western sanctions over the crisis in Ukraine and low energy prices.

Last year, Beijing clinched a USD-400-billion gas supply agreement with Moscow while in May Russia emerged as China's biggest source of crude oil.

"China-Russia relations are the best they've been for a long time," said Ji Zhiye, the vice president of China's Institute of Contemporary International Relations, adding, "Russia and China have a lot in common when it comes to views on global politics."

President Putin enjoys high popularity in China, mainly for his willingness to stand against the United States.