Chinese President Xi Jinping (R front) receives flowers upon his arrival in Ashkhabad for a state visit to Turkmenistan, Sept 3, 2013. [Photo/Xinhua]

ASHKHABAD -- President Xi Jinping arrived in the Turkmenistan capital on Tuesday on the first stop of his four-nation Central Asia tour.

The two nations are friendly neighbors and key strategic partners, Xi said during a speech on his arrival.

According to Xi, the two sides are scheduled to ink important political documents. A series of "weighty" cooperation agreements are also to be signed by government agencies and enterprises.

Turkmenistan is a key supplier of natural gas to China.

A gas pipeline, bringing supplies through China's western region, went into operation in December 2009.

The countries are expected to forge cooperation agreements on trade and energy during Xi's visit.

The tour of Central Asia will be Xi's third international excursion this year, and the first one to the neighboring region since he took office in March.

The tour, from Sept 3 to 13, also includes state visits to Kazakhstan, Uzbekistan and Kyrgyzstan.

It's widely expected that Xi's tour will help clarify the foreign policy of China's new leadership for the region.

Xi is also scheduled to attend the eighth Leaders' Summit of the Group of Twenty (G20) in St. Petersburg from Sept 5 to 6, as well as the summit of the Shanghai Cooperation Organization in Bishkek, the capital of Kyrgyzstan, on Sept 13.