Turkey's "two-headed" political model is unsustainable in the long term even if there is now great harmony between the president and prime minister and constitutional change is essential to prevent potential future crises, Deputy Prime Minister Mehmet Simsek said on Friday.

He said that Turkey's democracy will strengthen and that its integration with the European Union will continue in a very strong way, even as the country focuses on markets such as Russia, India, China and elsewhere in Asia.