The United States has threatened to levy more sanctions on the troubled Turkish economy if an American pastor who is being held on terror-related charges is not released.

"We have put sanctions on several of their cabinet members," Treasury Secretary Steve Mnuchin told Us President Donald Trump in a cabinet meeting attended by the press.

"We have more that we are planning to do if they don't release him quickly."

It comes after the White House condemned Turkey's decision to double tariffs on US cars, alcohol and tobacco imports, calling the action "a step in the wrong direction".

Turkey took the action in response to what it called the Trump's administration's attack on its economy.

The United States doubled tariffs on Turkish steel and aluminium last week, which contributed to a tumble in the Turkish lira, which has lost nearly 40% against the US dollar this year.

Qatar yesterday pledged $15bn in investment to Turkey, helping the lira recover some of its losses.

Tension between the two NATO allies have been strained amid Turkey's detention of American preacher Andrew Brunson.

Turkey has accused Mr Brunson of backing a coup attempt against President Recep Tayyip Erdogan two years ago.

The White House yesterday said the US would not lift sanctions on Turkish steel and aluminium products even if Mr Brunson was released.