President Vladimir Putin has praised what he calls Russia's "all-embracing and strategic partnership" with China, at the start of a visit to Beijing that comes against the background of a drop in trade and lingering mistrust.

Putin told Chinese Premier Li Keqiang that ties were based firmly on common economic interests, a reference to Russian hopes for Chinese investment and purchases of its oil, gas and other natural resources.

Leaders in both countries have extolled the blossoming strategic partnership between the former communist rivals, despite a major shrinkage in two-way trade and a slew of ambitious projects that have remained largely on paper.

Observers attribute the slow progress to Beijing's hard-nosed bargaining position and the Kremlin's deep-seated suspicions about the growing power of its mighty partner.