Turkey will take new measures to deal with a slide in the lira and will not refrain from "difficult" steps while remaining within free market economy rules, President Tayyip Erdogan said on Thursday.

In a speech to a traders' confederation in Ankara, Erdogan said nobody should carry out business in foreign currency apart from exporters and importers. Earlier on Thursday he ruled that property sales and rental agreements must be made in lira, putting an end to such deals in foreign currencies.

Erdogan also said that Turkey's central bank is independent and makes its decision on interest rates on its own, but added that his stance on high borrowing costs remained unchanged.

Speaking hours before a key decision by central bank on interest rates, Erdogan, a self-declared enemy of high interest rates, went on to criticise private banks saying some have increased their rates up to 50 percent.

Erdogan also told a traders' confederation that finance sector should help private sector by restructuring debts.