US President Donald Trump said he had doubled steel and aluminum tariffs on Turkey, adding to pressure on that nation's troubled economy amid a diplomatic row with Washington.

"I have just authorized a doubling of Tariffs on Steel and Aluminum with respect to Turkey as their currency, the Turkish Lira, slides rapidly downward against our very strong Dollar!" Trump said on Twitter.

"Our relations with Turkey are not good at this time!"

Mr Trump said he had authorised a 20% duty on aluminium and 50% on steel.

The lira crashed to a 19% daily loss against the dollar.

Turkey's Trade Ministry has said the additional tariffs are against the rules of the World Trade Organisation (WTO).

"Turkey expects other member countries to abide by international rules," the ministry said in a statement, adding that it would support steel and aluminium exporters in all international platforms.

It said the United States remains an important trade partner.

Turkey's President Tayyip Erdogan told Turks to exchange gold and dollars into lira as waves from the crisis spread abroad, with investors selling off shares in European banks with large exposure to the Turkish economy.

New Finance Minister Berat Albayrak - Mr Erdogan's son-in-law -acknowledged that the central bank's independence was critical for the economy, promising stronger budget discipline and a priority on structural reforms.

The lira sell-off has deepened concern about exposure to Turkey, particularly whether over-indebted companies will be able to pay back loans taken out in euros and dollars after years of overseas borrowing to fund a construction boom under Mr Erdogan.

His characteristic defiance in the face of the crisis has further unnerved investors.

The president, who says a shadowy "interest rate lobby" and Western credit ratings agencies are attempting to bring down Turkey's economy, appealed to Turks' patriotism.

"If there is anyone who has dollars or gold under their pillows, they should go exchange it for liras at our banks. This is a national, domestic battle," he told a crowd in the northeastern city of Bayburt.

People change money at an exchange office in Ankara 

"This will be my people's response to those who have waged an economic war against us."

The lira, which has lost a third of its value this year, fell on his comments and was trading at around 6.05 to the dollar after he spoke, nearly 9% weaker on the day.

"The dollar cannot block our path. Don't worry," Mr Erdogan assured the crowd.