Russian President Vladimir Putin said leaders from the SCO member and observer states will attend China's events marking the 70th anniversary of the end of the War of Resistance against Japanese Aggression (1937-45) in Beijing.
More countries have expressed their willingness to join the group, and the SCO would carefully study these applications, Putin added.
Chen Yurong, an expert on European-Central Asian Studies at the China Institute of International Studies, said the participation of India and Pakistan could shore up the group's international status and influence.
The six current members - China, Kazakhstan, Kyrgyzstan, Russia, Tajikistan and Uzbekistan - account for 60 percent of Eurasia's territory and a quarter of the world's population.
India, an emerging economy, would also expand economic cooperation and markets under the SCO framework, said Chen.
Shi Ze, a researcher with the China Institute of International Studies, said India and Pakistan play an important role in regional affairs including security, economy, counterterrorism and the peace process in Afghanistan.
Afghanistan, which borders Pakistan, China, Tajikistan and Uzbekistan, has been hit by terrorism and drug-trafficking.
During a meeting on Friday with Pakistani Prime Minister Sharif, Xi said China would work with Pakistan to play a constructive role in helping Afghanistan realize national reconciliation and peaceful development.
The Times of India said that the expected inclusion of India and Pakistan as full members of the SCO "opens up several opportunities" and, once actualized, would be the first time both countries were part of the same security group.
The SCO platform can also "become an important contact point between New Delhi and Islamabad to sort out their differences", said the newspaper.
Contact the writers at wujiao@chinadaily.com.cn.