On Friday, Trump authorized a doubling of tariffs on Turkish steel and aluminum imports - to 50 percent and 20 percent, respectively - ratcheting up a diplomatic dispute with the NATO-member country.
Turkey is world's sixth-biggest steel producer, and eighth largest steel importer for the USA according to the International Trade Administration.
Fears over contagion even pushed global equity markets lower, with some European banks coming under heavy selling pressure due to their exposure to Turkey.
"At the same time, the new USA sanctions against Russian Federation have unleashed concern in the German economy", he added. The Lira has lost almost a third of its value this year, as relations with the United States have become increasingly strained.
Trump intensified the alarm on financial markets with his new tweet doubling the tariffs, noting for good measure the lira was sliding "rapidly downward against our very strong Dollar!". He added, "Our relations with Turkey are not good at this time!".
Harsher US tariffs were likely to punish Turkey's already faltering steel exports to the United States.
However, the White House later clarified that Trump's announcement "authorised the preparation of documents" to raise the tariffs.
The latest tariffs stem from the trade fight Trump launched earlier this year with several countries, including Turkey, according to the Washington Post.
The Turkish president took aim at the United States in his address, claiming "some countries have engaged in behaviour that protects coup plotters and knows no laws or justice". "I am afraid there will be a bank run in Turkey, people rushing to withdraw their deposits". A 20 percent fall in exports would only reduce GDP by 0.1 percentage point or less per year in the 19 countries that use the euro currency.
Relations between Washington and Turkish President Recep Tayyip Erdogan also have worsened because of the detention of three locally employed U.S. consular workers, trade matters and differences over Syria.
Shares of Turkish steelmakers Kardemir Karabuk Demir Celik Sanayi ve Ticaret AS and Eregli Demir ve Celik Fabrikalari TAS plunged as much as 8 per cent and 9.9 per cent, respectively, after Trump's tweet.
On Thursday, Mr Erdogan said: "If they have their dollar, we have the people, we have Allah".
On June 21, Turkey's retaliatory tariffs went into effect on 4 to 70 percent of more than $1 billion worth of US goods. Turkey is prime among them. "But if the United States can't handle relations with Turkey ... then a further deepening of relations with Moscow is an option".
One of the hard issues affecting U.S. Gulen has denied the allegation.
Brunson, an evangelical Presbyterian from North Carolina, was jailed for allegedly supporting the group that Turkey blames for the failed coup and was moved from prison to house arrest in July. His cause resonates with Christian conservative supporters of Trump, who could be influential as Republicans seek to retain control of Congress in midterm elections in November.
"It's pretty remarkable how far the Trump administration is willing to go - putting at jeopardy the relationship with a North Atlantic Treaty Organisation ally over a preacher". He offered no further details.
Turkey imposed $266.5 million in tariffs against the USA in June, targeting American imports of coal, paper, walnuts, almonds, tobacco, whiskey and machinery, amongst other items.