Foreign Secretary William Hague condemns Syria’s attack on a Turkish jet as “outrageous” as the wreckage of the downed plane is found.
Turkish television said search and rescue teams had located the F-4 Phantom jet in Syrian waters at a depth of 1,300 metres.
Earlier on Sunday, the Turkish government said the plane had been hit by anti-aircraft fire while flying in international waters on Friday. Turkey will now formally consult with NATO allies – of which Britain is one – on a reaction.
Signals from both Turkey and Syria suggested neither wanted a military confrontation as a search operation for the two missing Turkish pilots continued.
Mr Hague said the incident called for “robust action” and repeated calls for the end of the rule of Bashar al-Assad in Syria.
William Hague said: “I am gravely concerned by the Syrian regime’s action in shooting down a Turkish military plane on June 22.
“When I spoke to Turkish Foreign Minister Davutoglu on 23 June, he told me that the plane had been shot down without warning.
“This outrageous act underlines how far beyond accepted behaviour the Syrian regime has put itself and I condemn it wholeheartedly.
“My thoughts and sympathies are with the families and friends of the missing Turkish pilots. I have made clear to Foreign Minister Davutoglu the UK’s strong support for the Turkish government at this difficult time.
The UK stands ready to pursue robust action at the United Nations Security Council. William Hague
“The Assad regime should not make the mistake of believing that it can act with impunity. It will be held to account for its behaviour. The UK stands ready to pursue robust action at the United Nations Security Council.
“This deplorable incident underlines the urgent need to find a solution to the current crisis in Syria in order to bring an end to the violence and to achieve a genuine political transition. We support the Joint UN and Arab League Special Envoy’s continuing efforts on this.”
Envoys from NATO member states will meet on Tuesday after Turkey requested consultations under article 4 of NATO’s founding Washington Treaty.
A NATO spokeswoman said: “The NAC (North Atlantic Council) will meet on Tuesday at Turkey’s request. We expect Turkey to make a presentation on the recent incident.”
Turkish Foreign Minister Ahmed Davutoglu is expected to make a statement later on Sunday, while the Turkish Prime Minister Tayyip Erdogan is scheduled to meet leaders of opposition parties to discuss the situation.
On Sunday, the Syrian state news agency said Syrian border forces had confronted “terrorists” who had infiltrated from Turkey and killed several of them.
The agency said the incident occurred near a Syrian border post in the province of Latakia. It did not give further details. The two countries share a border around 400 miles long.
Turkey is giving shelter to the rebel Free Syria Army and accommodating refugees on its southeastern border with Syria, some 30 miles from where the aircraft was shot down. But Ankara denies providing arms for the insurgents.