A woman walks past boards showing currency exchange rates in Moscow, Dec 16, 2014.(Xinhua Photo)

China's top diplomat is offering Beijing's assistance to Moscow, as pessimism is spreading about the uncertainties of the Russian economy.

With the Kremlin vowing to address Russia's dependence on oil and gas, more teamwork with China in non-energy sectors may help, but the key "lies in the hands of Moscow itself", analysts said.

Following the drastic drop of oil prices, the Russian rouble plummeted on Tuesday and has lost nearly 50 percent against the US dollar and the euro since March.

Foreign Minister Wang Yi told reporters on Saturday that "Russia has the capability and the wisdom to overcome the existing hardship in the economic situation".

"If the Russian side needs, we will provide necessary assistance within our capacity," Wang said.

Wang said China and Russia have been consistently supporting and helping each other.

Feng Yujun, a senior analyst of Russian studies at the China Institutes of Contemporary International Relations, estimated that "the hardest time for the Russian economy is just kicking off, with the upcoming three years clouded by major challenges".

The researcher pointed to a strengthening US dollar, and said emerging economies including Russia will suffer more as money increasingly flows back to the US.A major turnaround of the suffering economy "requires a range of measures to take effect", Feng said.

Russian President Vladimir Putin said on Thursday at an annual end-of-year news conference in Moscow that cooperation with China is one of the cornerstones of Russia's economic recovery and prosperity.

Zhang Deguang, a former Chinese ambassador to Russia, said Moscow has foreign currency reserves totaling hundreds of billions of dollars, and with such support the Russian economy "is still far away from being totally paralyzed".

Li Jianmin, a researcher at the Chinese Academy of Social Sciences, suggested that China's assistance be provided through mechanisms including the Shanghai Cooperation Organisation and BRICS.

Earlier this month, when Russian Prime Minister Dmitry Medvedev met in Astana, Kazakhstan, with Premier Li Keqiang, they agreed on enhancing cooperation in railways, infrastructure and the development of Russia's Far East region.

Loans, cooperation in major projects and participation in the domestic infrastructure investment in Russia are options on the table, Li added.

Qin Gang, the Foreign Ministry spokesman, told a news conference in Beijing on Thursday, "Please do not forget that China and Russia are highly complementary in the economic field, with broad areas and huge potential for cooperation."