Pakistan and Saudi Arabia signed a new strategic defence pact on Wednesday, with the two sides saying an attack on one country would be considered "an aggression against both."

The agreement comes just days after an Israeli strike targeted Hamas leaders in neighbouring Qatar, sending shock waves through the Gulf states that have long depended on the United States for their security.

"This agreement... aims to develop aspects of defence cooperation between the two countries and strengthen joint deterrence against any aggression," read a statement published by the Saudi Press Agency.

"The agreement states that any aggression against either country shall be considered an aggression against both," it added.

The deal was signed by Saudi Arabia's Crown Prince Mohammed bin Salman and Pakistan Prime Minister Shehbaz Sharif.

The signing of the pact comes just months after Pakistan and India fought an intense four-day conflict in May that killed more than 70 people on both sides in missile, drone and artillery fire, the worst clashes between the nuclear-armed neighbours since 1999.

India's Prime Minister Narendra Modi was visiting Saudi Arabia in April when he cut short his trip following a deadly shooting attack on tourists in India that sparked the conflict.

India and Pakistan – both nuclear powers – have long accused each other of backing militant forces to destabilise one another.

Saudi Arabia is believed to have played a key role in defusing the conflict.

It has been a key supplier of oil to India, the world's most populous country, for years.

India's rapidly developing economy relies heavily on petroleum imports, with Saudi Arabia ranked as its third-largest supplier according to the Indian foreign ministry.

Islamabad has also fostered close links with Saudi Arabia for decades, with over 2.5 million of its nationals estimated to be living and working in the kingdom.

The kingdom has long been a bulwark of economic support to help shore up Pakistan's faltering economy. (AFP)