Moscow: Russian Prime Minister Vladimir Putin on Tuesday left for China on a two-day visit during which he will hold talks with Chinese leadership but the much-awaited deal for delivery of natural gas is unlikely to be signed.

"The two sides will focus on the structure of bilateral trade, the expansion of mutual investment and cooperation in hi-tech industry, and the implementation of long-term  energy projects," Putin's foreign policy aide and deputy chief of PMO Yuri Ushakov said.

Ushakov, however, said the signing of official documents on the deliveries of Russian natural gas to China is not on the agenda of this visit.

A 'take-or-pay' agreement stating the basic terms of supplies of up to 68 BCM (billion cubic meters) of natural gas over a 30-year period to China was signed during Russian President Dmitry Medvedev's Beijing visit in September 2010.

However, Russian natural gas major Gazprom and China's CNPC have so far failed to close the deal due to price negotiations as Moscow was insisting on the European price.

According to Gazprom Deputy Chief Alexander Medvedev the sides had finally agreed on a price formula and the deal could be closed by the end of this year.

Putin, whose Beijing visit acquired a special importance after his announcement of plans to return to the Kremlin after March 2012 polls, is expected to meet with his Chinese counterpart Wen Jiabao and call on President Hu Jintao.

The two neighbouring nuclear giants with USD 70 billion bilateral trade are expected to sign about 20 bilateral agreements on cooperation in various areas, including modernisation of economy, agriculture and veterinary inspections, with the view of pushing bilateral trade turnover to USD 100 billion in the near perspective.