Russian President Vladimir Putin was officially welcomed to China on Friday by his Chinese counterpart Xi Jinping.
The state visit comes just a month after Putin began his new term in office, and underscores how mounting US pressure is drawing the two countries increasingly close.
Russia and China have responded to the US national security strategy describing them as America's top adversaries by vowing to further expand their economic, political and military cooperation.
They have also sought to strengthen the Shanghai Cooperation Organization, a regional grouping they created.
Beijing and Moscow's rapprochement is driven by a strong personal relationship between Putin and Xi, seen as the most powerful Chinese leader since Mao Zedong.
The two have met 25 times - five times last year alone, according to Putin's foreign affairs adviser, Yuri Ushakov.
