Central Asian heads of state converged in the historic city of Xian on Thursday for one-on-ones with President Xi Jinping to seal pledges of "enduring" friendship, and paving the way for the first in-person gathering of the six leaders.

The Foreign Ministry has said Xi will deliver an "important" speech and an "important" political document will be signed at the group meeting on Friday.

Across the Silk Road city of Xian, banners, billboards and even taxi signs were set up to promote the summit, with some in both Chinese and Russian.

The president of energy-rich Turkmenistan, the most distant of the Central Asian states from China, was the last of the five leaders to arrive, landing in Xian in the early hours of the morning on Thursday.

The first to land was President Kassym-Jomart Tokayev of Kazakhstan – the nation's largest trading partner in Central Asia - with his face-to-face meeting with Xi on Wednesday ending with a deal to build "enduring friendship" and share "weal and woe".

"We have a common goal – to intensify bilateral relations," Tokayev told Xi. "We are also united by the desire to strengthen regional and international security and cooperation."

The two sides agreed to take measures to ensure the safe and stable operation of the Kazakh section of the China-Central Asia natural gas pipeline. They also agreed to deepen cooperation in oil and uranium.

Tokayev's deal with Xi will set the tone for the other bilateral meetings, where China will seek deeper cooperation with other Central Asia states.

Two-way trade between China and Central Asia hit a record US$70 billion last year, with Kazakhstan leading with US$31 billion. Kyrgyzstan followed with US$15.5 billion, Turkmenistan with US$11.2 billion, Uzbekistan with US$9.8 billion and Tajikistan with US$2 billion. (Reuters)