Donald Trump has said he would have left the G20 summit over what he said was a show of Chinese "disrespect" to President Barack Obama upon his arrival.

Mr Obama did not receive a red carpet welcome, unlike other world leaders including Britain's Theresa May, when he landed in Hangzhou on Sunday morning.

The other leaders attending the summit had a red carpet laid on a rolling airport staircase. Mr Obama, however, used a smaller exit at the rear end of Air Force One.