President Xi once called President Putin his "best friend". The two have much in common: they are both authoritarian leaders, and both embrace the idea of a "multi-polar world" devoid of US domination. In Moscow they're expected to sign an agreement on "deepening the comprehensive partnership" between their two countries. The Chinese president's state visit is a clear sign of support for Russia - and its president - at a time when the Kremlin is under intense international pressure. And Russia's relationship with China is fundamental to withstanding that.
"Putin is building his own bloc. He doesn't trust the West anymore - and he never will again," believes journalist Dmitry Muratov, a former Nobel Peace Prize laureate.
