BEIJING - The cooperation between China and Russia is of strategic significance and will not be affected by outside factors, a Chinese foreign ministry official said on Wednesday.

"China and Russia are important partners to each other on trade and economic cooperation," Chinese vice Foreign Minister Cheng Guoping said during a news briefing on Premier Li Keqiang's upcoming visit to Germany, Russia, Italy and the UN Food and Agricultural Organization(FAO) headquarters from Oct. 9 to 15.

During his visit to Russia, Li will hold the 19th regular meeting between the two countries's prime ministers with his counterpart Dmitry Medvedev.

On the China-Russia relationship, Cheng said China is the number one trading partner of Russia and Russia is the number nine of China.

Two-way trade reached 89.2 billion U.S. dollars last year, and the two countries plan to raise the volume to 100 billion dollars by 2015 and 200 billion dollars by 2020.

"It is the common aspiration of the people of the two countries for them to expand and deepen cooperation," Cheng said, noting the inter-complementary advantages between the two countries in terms of geography, capital, market and technology.

"The cooperation between China and Russia is stable, and of long-term and strategic significance, which is not affected by the volatile international situation or (other) external factors," Cheng said.

As to Western countries' sanctions on Russia over the Ukraine crisis, Cheng said China always opposes imprudent sanctions or the threat of sanctions, "which we believe will not help to resolve problems."

"We welcome concerted efforts made by all sides concerned in pursuit of the momentum of a political solution to the Ukraine crisis, and hope all sides will continue working to alleviate tensions through dialogue and negotiations," said the official.