Saudi Arabia and nuclear-armed Pakistan signed a formal mutual defense pact on Wednesday, in a move that significantly strengthens a decades-long security partnership amid heightened regional tensions, Reuters reports.

The pact provides for a mutual response to any aggression, joint planning of military operations and expansion of defense cooperation, and covers all types of military assets, including Pakistan's nuclear capabilities.

Pakistani state television showed Pakistani Prime Minister Shehbaz Sharif and Saudi Crown Prince Mohammed bin Salman, the kingdom's de facto ruler, embracing after signing the agreement in Riyadh. In attendance was Pakistan's army chief, Field Marshal Asim Munir, regarded as the country's most powerful person.

Experts believe that the pact could shift the strategic calculus in a complex region. Allies of Washington, Gulf monarchies have sought to stabilize ties with both Iran and Israel to resolve longstanding security concerns.

"The agreement states that any aggression against either country shall be considered an aggression against both," a statement from the Pakistani prime minister's office said.

Israel's attempt to kill the political leaders of Hamas with airstrikes on Doha, while they were discussing a ceasefire proposal that Qatar is helping to mediate, infuriated Arab countries.

"This agreement is a culmination of years of discussions. This is not a response to specific countries or specific events but an institutionalization of longstanding and deep cooperation between our two countries," a senior Saudi official told Reuters when asked about its timing.

The senior Saudi official, who spoke on condition of anonymity, acknowledged the need to balance relations with Pakistan's rival, India, also a nuclear power.