Beijing has long sought to present the SCO as a counterweight to Western-led power blocs such as NATO and has pushed for greater collaboration between its 10 members.

Top diplomats from the grouping have arrived in Beijing for a meeting of the Council of Foreign Ministers, including Russia's Sergei Lavrov, India's Subrahmanyam Jaishankar and Iran's Abbas Araghchi.

Meeting Lavrov in the Chinese capital, Xi said the two countries should "strengthen mutual support on multilateral forums", according to state news agency Xinhua.

Beijing and Moscow should work to "unite countries of the global South and promote the development of the international order in a more just and reasonable direction", Xi said, according to Xinhua.

Russia's foreign ministry said in an earlier statement that "a number of issues of bilateral political contacts at the highest and high levels were discussed".

They included preparations for President Vladimir Putin's visit to China to join a SCO summit and World War II anniversary celebrations.

Russia's TASS news agency reported that Xi met Lavrov after the Chinese president held a "general meeting" with SCO foreign ministers.

- Trump's tariff threat -

The meeting and pledges of support came just hours after US President Donald Trump warned Russia that he will impose "very severe" tariffs against Moscow's remaining trade partners if it doesn't resolve its war in Ukraine within 50 days.

China, a diplomatic and economic ally of Moscow, in response said "coercion" by the United States would not resolve the conflict.

"China firmly opposes all illegal unilateral sanctions and long-arm jurisdiction. There are no winners in a tariff war, and coercion and pressure will not solve problems," Chinese foreign ministry spokesman Lin Jian said.

Lavrov met Sunday with his Chinese counterpart Wang Yi to discuss Ukraine and relations with the United States.

The Russian foreign minister arrived in China following a visit to North Korea, where he received assurances of support in its conflict with Ukraine.

Beijing claims to be neutral in the war but it has never denounced Russia's more than three-year military campaign, nor called for it to withdraw its troops.

Many of Ukraine's allies believe that Beijing has provided support to Moscow.

China regularly calls for an end to the fighting, while also accusing Western countries of prolonging the conflict by arming Ukraine.

Xi noted Tuesday that "political mutual trust among member states has deepened", according to state broadcaster CCTV.

The SCO "has successfully explored a path of regional cooperation that aligns with the trends of the times and meets the needs of all parties, setting a model for a new type of international relations," Xi said.