(Corrects paragraph 5 to show Saudi Arabia is also a signatory)
DUBAI, June 12 (Reuters) - A United Nations aviation body should declare Gulf Arab measures against Qatari air traffic as illegal, the chief executive of Qatar Airways said in comments to CNN published on Monday, after some Arab states cut ties with Doha in a diplomatic row.
Akbar Al Baker criticised Saudi Arabia, the United Arab Emirates and Bahrain for closing their airspace to Qatari flights a week ago.
He appealed to the International Civil Aviation Organization (ICAO), a U.N. agency which administers the Chicago convention that guarantees civil overflights.
"We have legal channels to object to this," he said. "ICAO... should heavily get involved, put their weight behind this to declare this an illegal act."
The UAE, Bahrain and Saudi Arabia have signed the convention.
Baker said 18 destinations were now out of bounds for the airline.
He also criticised Saudi Arabia and the UAE for shutting down the airline's offices.
"It is actually a travesty of civilized behaviour to close airline offices. Airlines offices are not political arms," he said. "We were sealed as if it was a criminal organization. We were not allowed to give refunds to our passengers."
He added that he was "extremely disappointed" in U.S. President Donald Trump.
"(The U.S.) should be the leader trying to break this blockade and not sitting and watching what's going on and putting fuel on (the) fire," he said.
Trump last week waded into the worst Gulf Arab rift in years and praised the pressure on Qatar, which Saudi Arabia, the UAE and Bahrain accuse of supporting Iran and funding Islamist groups, charges Doha denies.
In separate interview with the Wall Street Journal, Al Baker said he would not delay any plane orders or put expansion plans in other countries, such as India, on hold.
On Sunday Qatar Airways reported a 21.7 percent rise in net profit in its last financial year that ended in March, fueled by a strategy of investment and expansion. (Reporting by Sylvia Westall, editing by Louise Heavens)