Regional leaders on Tuesday arrived in Pakistan's capital Islamabad to attend the Shanghai Cooperation Organisation (SCO) summit.

Security in the city is tight for the 23rd SCO summit, with Pakistan deploying 10,000 security personnel, including the army.

The SCO is the world's largest regional bloc in terms of geographic scope, and covers more than 40 percent of the world's population.

Shakeel Ahmad Ramay, CEO of the Asian Institute of Eco-Civilisation Research and Development, said enhancing economic opportunities will be high on the summit's agenda.

"China is creating economic linkages through trade and establishing special economic zones," he said.

"In the last few years, China has increased its trade with SCO members, it's around US$383 billion right now."

Another topic that will likely top the agenda, according to Ramay, is regional cooperation to combat terrorism, which has been a big issue for host Pakistan, with the country suffering the recent deadly attacks in Karachi in early October.

Ramay also said that more countries, like Saudi Arabia, are looking to join the SCO, but he underscored the difference between the SCO and other regional groups.

"SCO is a partnership organisation, not an alliance or a bloc, like BRICS, thus leaves it more to its members to decide to what extent they want to enhance cooperation," he said.

Earlier, Premier Li Qiang received the honour guard at the Prime Minister's House, where he met his Pakistani counterpart, Shehbaz Sharif, ahead of the summit.

Sharif and Li discussed economic and trade ties and cooperation under the China-Pakistan Economic Corridor, or CPEC, a US$65 billion investment in the South Asian country under the Belt and Road Initiative.