Saudi Arabia's civil aviation authority said on Tuesday that the closure of its airspace to flights from Qatar was within the kingdom's sovereign right to its citizens from any threat.
The agency was commenting in reaction to remarks made by Qatar Airways' chief executive that Saudi Arabia, the United Arab Emirates and Bahrain were violating international law by shutting out Qatari flights.
The airspace closure was to protect the country and its citizens from anything it sees as a threat and as a precautionary measure, Saudi Arabia's General Authority of Civil Aviation said in a statement published by the Saudi Press Agency.
Similar statements were also issued by the UAE and Bahraini aviation authorities after Qatar Airways Chief Executive Akbar al-Baker criticized the three Arab countries for the airspace closure in an interview with CNN.
The United Arab Emirates and Qatar have long been major proponents of open-skies air transport agreements which remove restrictions on flying between states.
These policies helped the region's largest airlines -- Emirates, Etihad Airways and Qatar Airways to develop their home airports as hubs linking passengers traveling between the east and west.
"From an industry viewpoint it's unfortunate and disappointing when airlines get caught up in broader political sensitivities which inhibit the benefits of competition and consumer choice, which the region is renowned for," independent aviation consultant John Strickland told Reuters.
Saudi Arabia, the UAE, Bahrain and Egypt cut diplomatic and transport ties with Qatar a week ago, accusing it of fomenting regional unrest, supporting terrorism and getting too close to Iran, all of which Doha denies.
In all 18 destinations in the region are now out of bounds for Qatar Airways, which has also been forced to close its offices in Saudi Arabia and the UAE.
Qatar Airways will now use the aircraft that had been operated on those 18 destinations to fast track its expansion plans, al-Baker later told Al Jazeera in an interview on June 13.
Al-Baker, warning that the blocking of airspace would also hurt competitors by undermining confidence in the region's "air connectivity", did not say which markets it would expand to.
Meanwhile al-Baker has appealed to the International Civil Aviation Organization, a U.N. agency which regulates international air travel under the Chicago Convention, to declare the airspace closure as illegal.
The UAE's General Civil Aviation Authority said it was fully committed to the Chicago Convention but reserved the sovereign right under international law to take any precautionary measures to protect its national security if necessary, UAE state news agency WAM said.
The three countries' aviation authorities also said that non-Qatari private and chartered flights from Qatar must submit requests to them at least 24 hours before crossing the airspace.
The request should include a list of names and nationalities of crews and passengers, as well as the cargo carried by the aircraft, they said.