Turkish prosecutors detained 10 of the admirals on Monday and ordered four others to turn themselves in after they published an opened letter critical of the proposed Canal Istanbul over the weekend.

"The duty of retired admirals -- 104 of whom come together -- is not to publish declarations that hint at a political coup," Erdogan said.

"In a country whose past is filled with coups, (another) attempt by a group of retired admirals can never be accepted," he said after the former commanders criticised his plans for Canal Istanbul.

Officials last month approved a project to develop a new 45-kilometre (28-mile) shipping lane comparable to the Panama or Suez canals but it has raised questions over Turkey's commitment to the Montreux Convention.

The 1936 pact is aimed at demilitarising the Black Sea by setting strict commercial and naval rules on passage through the Bosphorus and Dardanelles straits leading to the Mediterranean.

The retired admirals worry that the new canal's construction would result in Turkey abandoning the 1936 treaty, angering Russia and losing its neutrality in the volatile region.

Erdogan said it was "completely wrong" to link the proposed canal to the treaty.

But he added that the proposed canal "will reinforce our sovereignty", hinting that Turkey could withdraw from the pact at a later date.

"We don't have any intention to withdraw from Montreux now," Erdogan said in televised remarks.

"But if the need emerges in the future, we could revise every convention to help our country get better."