Beijing: China's imports of oil from Russia rose 55 percent in May, customs data showed on Monday, with the West sanctioning fuel imports from Moscow over its invasion of Ukraine.

The world's second-biggest economy imported around 8.42 million tonnes of oil from Russia last month, surpassing its shipments from Saudi Arabia, as Beijing refuses to condemn Moscow's war.

Last week, President Xi Jinping assured Vladimir Putin of China's support on Russian "sovereignty and security," and Beijing has also been accused of providing diplomatic cover for Moscow by blasting Western sanctions and arms sales to Kyiv.

The customs data comes four months into the war, with other buyers avoiding Russian energy imports.

The number was also a spike from the 5.44 million tonnes China imported in May 2021, according to figures from the Customs Administration, and helped Russia overtake Saudi Arabia as China's main source of oil.

Earlier this month, Chinese state media said Beijing was willing to "intensify strategic coordination between the two countries".

The Kremlin said the two leaders had agreed to ramp up economic cooperation in the face of "unlawful" Western sanctions.

The West has adopted unprecedented sanctions against Russia in retaliation for its invasion of Ukraine, and Moscow is looking for new markets and suppliers to replace the major foreign firms that left Russia following the invasion.