China has assured Islamabad of its support in defending its sovereignty and territorial integrity even while welcoming on Tuesday the restoration of diplomatic ties between Tehran and Islamabad after their recent air strikes against each other.

As China's Foreign Minister Sun Weidong visited Pakistan on a mediation mission, a statement from Foreign Ministry on Monday said it is maintaining close contacts with Pakistan and Iran to 'bridge their differences'.

China on January 18 offered to play a 'constructive role' to ease tension between Pakistan and Iran following their missile strikes against each other and asked the two countries to 'exercise restraint and calmness and avoid escalation'.

Earlier on January 18, Pakistan conducted 'precision military strikes' against what it called 'terrorist hideouts' in Iran's Siestan-Balochistan province that killed nine people.

The attack was seen as retaliation to Iranian missile and drone attacks on January 16 which targeted two bases of the Sunni Baloch militant group Jaish al-Adl in Pakistan's unruly Balochistan province.

Commenting on China's mediation efforts to dial down Iran-Pakistan tensions, Chinese Foreign Ministry spokesperson Wang Wenbin told a media briefing in Beijing on Tuesday that 'China welcomes the good progress that Iran and Pakistan have made in repairing their ties and supports them in further enhancing mutual trust and deepening cooperation through friendly consultation'.

China and Pakistan are all-weather strategic cooperative partners, Sun was quoted as saying by the Chinese Foreign Ministry about his meeting with Pakistan's President Arif Ali on Monday.

Sun is a former Ambassador to Pakistan and India both.

China appreciates Pakistan's firm adherence to the one-China principle and 'supports Pakistan in safeguarding its sovereignty, independence and territorial integrity', as well as its unity, stability, development and prosperity, Sun told Alvi.

He also said, China is willing to work with Pakistan to follow through on the important common understandings reached between the leaders of the two countries, deepen political mutual trust, expand practical cooperation, upgrade the China-Pakistan Economic Corridor (CPEC), and 'accelerate the building of a closer China-Pakistan community with a shared future in the new era'.

Sun held talks with a host of Pakistan officials including the Army Chief General Syed Asim Munir during which too he assured China's support to Pakistan in defending its sovereignty and territorial integrity.

He also took part in the key meeting of $60 billion CPEC over which India protested as it is being laid through the Pakistan-Occupied Kashmir (PoK).

Wang Wenbin reiterated its stand on mediation and said in response to a question: "We stand ready to work with Iran and Pakistan to strengthen mutually beneficial cooperation and safeguard regional peace, stability and development."

Iran and Pakistan have mutually agreed that the ambassadors of both the countries may return to their respective posts by January 26.

Following the air strikes against each other, the two countries had expelled the others' envoys.

The attacks had put China in a piquant situation as Pakistan is an all-weather ally, while Iran is warming up to Beijing in recent years enabling China to expand its influence in the West Asia region.

China also imports a considerable amount of oil from Iran.

Meanwhile, Vice Foreign Minister Ma Zhaoxu in a phone call with Iranian Deputy Foreign Minister Ali Bagheri Kani asked him to dial down tensions while Sun visited Islamabad from January 20 to 22.

China is also concerned over Iran's missile strikes in Baluchistan where most of its investments are located especially, the Gwadar port, the starting point of the CPEC project that connects to China's Xinjiang province.