President Hu Jintao shakes hands with?Turkmenistan's President Gurbanguly Berdymukhamedov?during their meeting on Wednesday in Beijing. Turkmenistan has agreed to substantially increase natural gas supplies to China. Xu Jingxing / China Daily

BEIJING - Energy-rich Turkmenistan will increase its natural gas deliveries to China by two-thirds under an agreement signed on Wednesday, with leaders of the two countries vowing to establish a long-term and stable strategic energy partnership.

The agreement, signed by President Hu Jintao and Turkmen President Gurbanguly Berdymukhamedov after a meeting on Wednesday morning, will increase annual gas deliveries by 25 billion cubic meters a year, bringing the annual total to 65 billion cubic meters "in the near future", Berdymukhamedov told reporters after the signing ceremony.

The figure - 65 billion cubic meters - is equivalent to more than half of China's entire natural gas consumption last year.

During their meeting, Hu also pledged to deepen energy cooperation with Turkmenistan and establish "a long-term and stable strategic energy partnership" following the success of a natural gas pipeline between the two countries, which became operational in 2009.

China, the world's second-largest economy, has been diversifying and expanding access to energy needed to power its fast-growing economy and reduce its reliance on heavily polluting coal.

Turkmenistan has adopted a diversified energy export strategy to shake off its dependence on sales to Russia. Besides expanding gas exports to nearby Iran and launching a pipeline to China, it has also won strong support from the European Union and the United States for plans to supply gas to a trans-Caspian pipeline that will run to Europe via Azerbaijan.

Gao Fei, a researcher on Central Asia studies at China Foreign Affairs University in Beijing, said the signed natural gas agreement would greatly assist China in diversifying its energy sources.

China and Turkmenistan launched a natural gas pipeline in Central Asia in December 2009. The 1,833-km pipeline is the longest in the world and had delivered 10 billion cubic meters of natural gas to China by the end of May this year.

The gas agreement was one of 14 signed following the leaders' talks on Wednesday. Others cover loans for the purchase of oil and gas drilling equipment, public security cooperation, recognition of degrees, combating money laundering and tackling terrorism.

"China highly values its relations with Turkmenistan," said Hu, adding that it is a policy of the government to develop friendly and cooperative relations with Turkmenistan on the basis of mutual respect, equality and mutual benefit.

Considering China as a top-priority strategic partner of Turkmenistan, Berdymukhamedov, who is in China for a four-day visit, told Hu his country appreciates China's respect for Turkmenistan's neutral status.

Both sides agreed to enhance security and law enforcement cooperation, promising joint efforts to fight terrorism, separatism and extremism, and cross-border crimes. China became Turkmenistan's largest trade partner in 2011, with bilateral trade rising to $3.56 billion in the first three quarters.