The purchase, valued at $60-70 million, is one of Tehran’s largest-known efforts to strengthen its short-range air ‌defences since the outbreak of its war with the US and Israel, which exposed gaps in Iran’s ability to protect military sites and strategic infrastructure.

The contract covers the purchase of between 300 and 400 man-portable air defence systems (MANPADS), including Chinese-made QW-12 and FN-16 missiles, the sources said.

The deal was signed with Zhongqing Baoshang International Investment, a Hong Kong-based company that the sources said was acting as an intermediary between the Iranian ​side and the Chinese supplier.

Iran needs to rearm

The sources spoke on condition of anonymity because of the sensitivity of the matter.

Iran’s foreign ministry ​did not immediately reply to a request for comment.

China’s Foreign Ministry said: “The relevant reports are completely groundless. China has consistently played a role ⁠in promoting peace and ending the conflict.”

Beijing-based Zhong Qing Bao Shang Group, the parent company of Zhongqing Baoshang International Investment, did not immediately respond to an email request for comment ​on Tuesday.

Iran needs to rearm after months of fighting in which the US and Israel have struck facilities linked to its missile, drone and air-defence programmes, and Tehran responded with barrages of ​ballistic missiles and drones.

The conflict has highlighted the challenge of defending fixed military and strategic sites against advanced aircraft and precision-guided weapons.

Washington abruptly suspended two weeks of bombardment on Saturday, but President Donald Trump said strikes would resume if negotiations failed to end the five-month-old conflict, which has in theory been in a state of ceasefire since April.

The delivery of hundreds of MANPADS would significantly expand Iran’s inventory of short-range ​air-defence weapons and underscore how military ties with China are deepening.

The sources cautioned that, although the agreement had been signed, delivery schedules, quantities and other implementation details could still change.

Less vulnerable

While Iran has invested heavily in the past two decades in missiles, drones and radar, military experts say portable air-defence systems are important because they can be dispersed quickly, operated by small teams and relocated frequently, making them less vulnerable than fixed air-defence ​batteries.

A European security source said authorities in his ​country were aware of several contracts under ⁠discussion involving the possible sale of QW-series MANPADS to Iran, including QW-12, QW-18 and QW-19 systems.

A second security source, in the Middle East, said Iran had been seeking to purchase QW-12 and QW-18 missiles, but they were unaware that a deal had already been concluded.

The QW-12 ​and FN-16 are shoulder-fired, infrared-guided surface-to-air missile systems designed to engage low-flying aircraft, helicopters and drones.

Their mobility allows them to be ​deployed rapidly around military installations, ⁠energy infrastructure and other sensitive sites.

Defence analysts regard the QW-12 as less capable than newer QW variants, including the QW-18 and QW-19, but say the systems can still provide an effective layer of short-range protection against drones and low-flying targets.

Two Western intelligence sources and an Iranian official said Tehran had also explored the use of overland routes to move Chinese military supplies and dual-use components ⁠more discreetly and ​reduce the risk of disruption.

The procurement highlights the Islamic Republic’s continuing reliance on a combination of domestic weapons ​production and foreign suppliers despite years of sanctions and restrictions on defence-related imports.

Reuters previously reported that Iran was close to securing a separate agreement with China to acquire anti-ship cruise missiles, according to people familiar with those negotiations.

Reuters ​could not determine whether the agreement went through.