Donald Trump
Donald TrumpReuters

U.S. President Donald Trump said on Friday he had authorized higher tariffs on imports from Turkey, imposing a 20 percent duty on aluminum and a 50 percent duty on steel.

Tension has been mounting between the two NATO allies over Ankara's imprisonment of an evangelical pastor and other diplomatic issues.

"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 in an early morning post on Twitter. "Aluminum will now be 20 percent and Steel 50 percent."

"Our relations with Turkey are not good at this time!", he concluded.

Meanwhile, Turkish President Recep Tayyip Erdogan called on the country’s citizens to sell foreign currencies to support the lira which has seen a record plunge against the US dollar.

"Change the euros, the dollars and the gold that you are keeping beneath your pillows into lira at our banks. This is a domestic and national struggle," Erdogan said, as quoted by the Associated Press.

According to the RT news agency, the Turkish currency dropped more than 11 percent on Friday, hitting a new low of 6.3 lira to the US dollar. The currency is currently heading for its worst week since 2001.

The latest diplomatic spat between Washington and Ankara was sparked by the arrest of US evangelical pastor Andrew Brunson on terrorism charges in Turkey. Brunson was detained in connection with the failed military coup in 2016 to oust the country's president.