Chinese President Xi Jinping left Tuesday for state visits to Kazakhstan and Tajikistan, during which he will attend a meeting of Shanghai alliance nations in the Kazakh capital Astana.

The nine-member Shanghai Cooperation Organisation (SCO), which encompasses a vast stretch of the globe from Moscow to Beijing, includes around half the world's population.

Its permanent members are this year's host Kazakhstan, India, China, Kyrgyzstan, Pakistan, Russia, Tajikistan, Uzbekistan and, as of last year, Iran.

This year, Belarus is expected to join after being told at 2023's SCO summit, hosted virtually by India, that it would become a member.

"Chinese President Xi Jinping left Beijing on Tuesday morning for the 24th Meeting of the Council of Heads of State of the Shanghai Cooperation Organisation in Astana, and state visits to Kazakhstan and Tajikistan at the invitation of President Kassym-Jomart Tokayev of the Republic of Kazakhstan and President Emomali Rahmon of the Republic of Tajikistan," state news agency Xinhua said.

Xinhua reported that Xi's entourage included Cai Qi, a top-ranking member of the Chinese Communist Party, and Foreign Minister Wang Yi.

China's foreign ministry spokeswoman Mao Ning on Monday said Beijing believed the SCO summit would "help build more consensus among all parties and make contributions to promoting security, stability and development of member countries", and advance "lasting peace and common prosperity in the world".

- 'In depth' talks -

During Xi's trip to Kazakhstan -- his fifth -- he will attend various state events, including a welcoming ceremony, signing ceremony and a banquet.

He will hold "in depth" talks with President Tokayev "on bilateral relations, cooperation in key areas, and the regional and international landscape", Mao said.

Xi will then head to Tajikistan for his second state visit to China's western neighbour, where he will "make new plans for the growth of China-Tajikistan relations" with President Rahmon, according to the spokeswoman.

Beijing has ramped up diplomatic efforts in Central Asia, with Xi calling for a deepening of economic ties during a summit China hosted last May that was attended by leaders of several countries in the region.

Central Asia is a vital link in China's flagship Belt and Road international infrastructure development project.

Beijing has sought to fill a void in the region created by Moscow's 2022 invasion of Ukraine, as former Soviet states worry about an increasingly bellicose Russia.

The Central Asia summit last May saw China pledge to expand transport links with the region and forge ahead with a Central Asia-China gas pipeline.

After the Astana meeting, China will assume the SCO's rotating presidency for the 2024-2025 period.