Pakistan and India will start the process of joining a security bloc led by China and Russia at a summit in Russia later this week, a senior Chinese diplomat said on Monday.

The Shanghai Cooperation Organisation (SCO) groups China, Russia and the former Soviet republics of Tajikistan, Uzbekistan, Kazakhstan and Kyrgyzstan, while India, Pakistan, Iran, Afghanistan and Mongolia are observers.

"As the influence of the SCO's development has expanded, more and more countries in the region have brought up joining the SCO," Chinese Vice Foreign Minister Cheng Guoping told a news briefing.

"India and Pakistan's admission to the SCO will play an important role in the SCO's development it will play a constructive role in pushing for the improvement of their bilateral relations," he said.

Cheng said that the summit, to be attended by Chinese President Xi Jinping, would also discuss security in Afghanistan.