The Pentagon said late on Friday it was closely monitoring developments in Turkey and reports of a military coup there but played down suggestions that the rebellion would mean an immediate withdrawal of the US military presence in the country, crucial in the fight against Isis.

Notably, the defence department in Washington was at pains to stress that the key US airbase at Incirlik was still functioning as normal in spite of the chaotic scenes being reported from the two largest cities of Ankara and Istanbul.

“We are monitoring the situation in Turkey closely and are taking appropriate steps to ensure the safety and security of our service members, civilians, their families, and our facilities. As of this time, there has been no impact to Incirlik Air Base and counter-ISIL air operations from Incirlik continue,” a senior Pentagon official said in a statement.

Traditionally, the US would be impelled to end any kind of military operations in a country where a democratically elected government is overthrown by its own military establishment.

Because Turkey is a key member of Nato in an absolutely vital geo-strategic position on the border between the Middle East and western Europe any events that forced a withdrawal by the US would represent a diplomatic and military disaster for the US and for the Alliance as a whole.

Turkey coup - 60 dead in 'act of treason' against the government

Most importantly, Turkey and its bases have proved pivotal in the Alliance’s efforts to counter the rise of Isis in Syria and Iraq. Many of the aerial US sorties flown to seek out Isis larges originate in Incirlik.

However, with fluctuating reports on how successful or otherwise the military mutiny is turning out to be, it is understandable that for now the US will stand back to see how events play out before taking any longer term decisions.

Reports that the plane carrying President Tayyip Erdogan had successfully borne him from his holiday location on the Mediterranean coast and landed in Istanbul was clearly being taken as an encouraging sign that government claims that the situation had been bought under control may prove to be true.

Both the US Secretary of State, John Kerry, and President Barack Obama issued statements earlier underscoring the support of the government, stressing that it has been democratically elected and therefore must be supported. Mr Kerry is in the region and US officials said he and Mr Obama had been discussing the crisis by telephone.

Kerry said he had stressed in a telephone call with Turkish Foreign Minister Mevlut Cavusoglu the United States' “absolute support” for Turkey's democratically elected, civilian government and democratic institutions.