The first visit to Pakistan by a top Indian diplomat in nearly 10 years was an "ice breaker", the information minister said Wednesday, as regional heads of governments gathered for a Shanghai Cooperation Organisation (SCO) summit.

Nuclear-armed India and Pakistan are bitter adversaries with longstanding political tensions, having fought several wars and numerous smaller skirmishes since they were carved out of the subcontinent's partition in 1947.

"Neither us nor them requested for a bilateral meeting... but I believe his arrival here is an ice breaker," the information minister Attaullah Tarar said on the sidelines of the summit in the capital Islamabad.

"Yesterday, when all the leaders were being welcomed and there were handshakes, I think positive images were sent out globally."

Indian Foreign Minister Subrahmanyam Jaishankar and Pakistan Prime Minister Shehbaz Sharif greeted each other with a handshake and sombre expressions at the start of an official dinner for the visiting leaders of the SCO bloc on Tuesday.

Relations between neighbours India and Pakistan have been particularly sour since 2019, when Prime Minister Narendra Modi revoked the limited autonomy of Indian-administered Kashmir.

Modi's 2019 move was celebrated across India but led Pakistan to suspend bilateral trade and downgrade diplomatic ties with New Delhi.

The Himalayan region of Kashmir is divided between India and Pakistan but claimed by both in full, with each accusing the other of stoking militancy there.

Premiers from SCO member states China, Russia, Belarus, Kazakhstan, Uzbekistan, Tajikistan and Kyrgyzstan all attended the meeting in a Pakistani capital that was locked down by tight security.

In his address, Jaishankar stressed the importance of "mutual trust, friendship and good neighbourliness".

"If activities across borders are characterised by terrorism, extremism and separatism, they are hardly likely to encourage trade, energy flows, connectivity and people-to-people exchanges in parallel," he said.

Sharif opened the meeting on Wednesday with an address in which he called on the China- and Russia-led bloc to ensure "collective security" and cooperation for "sustainable development and prosperity for the SCO region".

He called on leaders to prevent militant groups from flourishing in Afghanistan.

"The international community must step forward" to press the Taliban government and "ensure Afghan soil is not misused for terrorism against its neighbours", Sharif said.

Afghanistan, at a crossroads between the bloc's members, presents "an invaluable and rare opportunity for trade and transit benefitting all SCO member states", he said.

It has observer status at the SCO but has not been invited to international conferences since the Taliban ousted the Western-backed government in Kabul three years ago.