Washington: Newly-released video footage from Pyongyang media shows US President Donald Trump returning a salute to a North Korean military general during the Singapore summit, an extraordinary display of respect from an American leader.

Returning a salute from a military officer of a friendly foreign nation is common practice for US military officers and considered a display of military professionalism. There is no rule that a US president is obliged to return a salute, which is considered a sign of mutual respect, reports CNN.

After Trump and North Korean leader Kim Jong-un walked down a colonnade to shake hands at the Capella Hotel on Tuesday, they entered into a room filled with various members of Kim’s delegation, the video from North Korean broadcaster KCTV news shows.

Trump starts to shake hands with those in the room. Upon encountering North Korean General No Kwang-chol, who was in full uniform, Trump first extends his hand, to which the general responds with a salute.

Trump then salutes back, extends his hand again and the two men shake hands.

A US official told CNN that Trump was briefed on protocol, which is to not salute military officers from other countries.

The White House, however, is not viewing Trump saluting a North Korean general as a mistake. It is being seen as all part of the broader goal that day, which was to show respect to Kim and his entourage, according to the official.

During Thursday’s White House media briefing, press secretary Sarah Sanders said Trump was just using ‘common courtesy’.

‘It’s a common courtesy when a military official from another government salutes, that you return that,’ Sanders said.

Trump frequently salutes people he sees in a military uniform.

Trump’s salute also evokes criticism President Barack Obama received early in his presidency when he bowed to the Saudi Arabian king.

At the time, Trump called Obama an ‘amateur’.