US diplomats sent a letter criticizing Pakistani air force commander after it used F-16 fighters to shoot down Indian aircraft.

US Deputy Secretary of State for Arms Control and International Security Andrea Thompson wrote in August to Pakistan air commander Mujahid Anwar Khan to reprimand the country of "transferring, maintaining, and operating" fighters. The F-16 and US-made AMRAAM missiles at forward combat bases are not allowed in arms trading agreements between the two countries.

"We understand that Pakistan's transfer of these fighters is for defense purposes, but the US government considers deploying them to bases that are not approved by the United States as a cause of concern, incompatible. F-16 fighter deal, "Thompson said.

Although the US official did not mention it directly, the letter was considered a response of Washington after the Pakistani air force claimed to have used F-16 fighters to shoot down the Indian MiG-21 fighter in the air battle. Kashmir sky late February.

"Such actions could put US sensitive technology in the hands of a third party, adversely affecting the infrastructure and security platforms shared between the two parties," the letter read.

Thompson, a former US Army colonel, left the US State Department in September and the letter he sent to the Pakistani air commander was only published by the US media on December 11.

India in March displayed missile fragments with the words "AIM-120C-5", a US-made medium-range surface-to-air missile and fitted to Pakistan F-16 fighters, accusing it of being a fruit. The bullets shot down the MiG-21. Islamabad denied the claim, claiming a fighter locked the target on Indian aircraft for deterrence and then launched missiles into the field to avoid casualties.

The F-16 purchase agreement between Washington and Islamabad comes with a series of restrictive provisions, in which the US requires the aircraft to be used only for the purpose of "strengthening the ability of anti-terrorism operations." Pakistan "and can only be stationed at certain bases. Pakistan's deployment of F-16 dogfight with India is considered a violation of the agreement, making it possible to face sanctions from the US.

The US State Department and the Pakistani embassy in the US did not comment on this information.

Many diplomats have suggested that Thompson purposely did not mention allegations of Pakistan F-16 fighters shooting down Indian MiG-21 aircraft, as this could become evidence that Islamabad violated the terms of the agreement and forcing Washington to launch sanctions at a time when the Trump administration is seeking to restore ties with its South Asian allies.

The biggest air battle between Pakistan and India since 1971 erupted in the skies over Kashmir after the Indian air force attacked a site believed to be a terrorist camp in Pakistan. After the dogfight, the Indian army was heavily criticized for losing its MiG-21 fighter and the pilot was taken prisoner. Tensions between the two countries cooled after Pakistan returned pilots to the Indian side.