Beijing has said it was willing to mediate tensions between Pakistan and Iran, after the two countries traded deadly air strikes on militant targets on each other's territory.

China is a close partner of both nations, who enjoy extensive military and economic ties with Beijing and play important roles in its geopolitical ambitions.

Here's what you need to know about how Beijing could be uniquely positioned to mediate the tensions:

- Close economic ties -

Straddling Central Asia and a vast territory from the Himalayas to the Persian Gulf, Pakistan and Iran are well-positioned in Beijing's long-term plans to reshape regional geopolitics in its own interests.

Beijing's foreign ministry spokeswoman Mao Ning said Thursday that China was "willing to play a constructive role in de-escalating the situation" if both sides wished.

"China commands influence and leverage in both capitals, and both countries expect a rising China to dominate Asia for decades to come," Sameer P. Lalwani, a senior expert on South Asia at the US Institute of Peace (USIP), told AFP.

"Beijing possesses some credibility to press the leaderships of both countries for cooler heads to prevail."

Pakistan is one of Beijing's closest partners, and the two have long described ties as "deeper than oceans, higher than mountains, sweeter than honey, and stronger than steel".

The South Asian power also plays an important role in Beijing's Belt and Road Initiative (BRI), earmarking tens of billions of dollars for a range of transport and energy projects connecting western China with Pakistan's Gwadar Port -- described as an "economic corridor".

Tehran and Beijing have also deepened trade ties in recent years, though Beijing's efforts to pull Iran into the BRI have been complicated by sanctions and many of the details of a 25-year cooperation agreement signed in 2021 remain murky.

China is Iran's largest trade partner and a top buyer of the Central Asian power's sanctioned oil -- analysis firm Kpler last year said Chinese imports of Tehran's petroleum had soared to a 10-year high, Bloomberg reported.

"In some ways, Iran and Pakistan may be competitors vying for Beijing's economic and strategic investments," Lalwani said. 

- Military nexus -

This week's cross-border clashes between Iran and Pakistan came as a surprise: while they often accuse each other of allowing militants to operate from the other's territory, cross-border operations by government forces are not common.

Both heavily armed militaries enjoy close ties with Beijing.

China has long played a critical role in arming Iran, aiding its efforts to modernise its military hardware and tactics as well as "transfer of technology and machinery" for its illicit nuclear program, according to the RAND Corporation.

Military cooperation is also a central pillar of the "stronger than steel" China-Pakistan friendship.

Beijing is Islamabad's top provider of conventional weapons -- and its dominant supplier of "higher-end offensive strike capabilities", according to a paper by USIP's Lalwani.

The two also conduct extensive joint military training, last November holding their largest-ever naval drills in and around the key Pakistan port city of Karachi, Beijing's state media said.

"Military ties between Beijing and Islamabad have become increasingly close and substantial," said Bjorn Alexander Duben, an assistant professor at China's Jilin University.

That, he said, might give Beijing leverage to "urge restraint" when tensions flare.

- Middle man -

Beijing's case to oversee an effort to cool Pakistan-Iran tensions could also be bolstered by recent efforts to play diplomatic mediator, albeit with mixed results.

Last year saw it broker a surprise thaw of ties between Iran and its long-time Middle East rival Saudi Arabia.

But other moves have been less successful: Beijing's efforts to push for a "political settlement" to the Ukraine conflict floundered last year after Western countries said it could enable Russia to hold much of the territory it has seized.

And China's attempt to pitch itself as an intermediary between Arab states and Israel following the outbreak of conflict with Hamas has yielded little results. 

Nevertheless, analysts think Beijing's leverage with both Islamabad and Tehran could help it play a role in cooling tempers.

"Both Pakistan and Iran are key partners (for China) due to their geography," Masood Khalid, Pakistan's former ambassador to China, told AFP.

"Pakistan has had a stable relationship with Iran notwithstanding the current tension," he added.

"I think they will find an amicable way out to defuse the situation."