The tariff for steel imported from Turkey will now be 50 percent. He did not specify any countries.
A Turkish man waits to change his USA dollars with Turkish liras inside a currency exchange shop in Ankara, Aug. 10, 2018.
"Interest rates should be kept to a minimum because they are a tool of exploitation that makes the poor poorer and the rich richer", he said.
But Erdogan said Turks should not be alarmed by exchange rate movements.
The Trump administration imposed financial sanctions against two ministers of President Recep Erdogan's cabinet, a move that sent the Turkish lira plummeting. The sides held talks in Washington this week but failed to resolve the spat.
Washington is in a standoff with Ankara over the imprisonment and house arrest of American pastor Andrew Brunson. Since then Trump and his vice president Mike Pence have repeatedly called for his release while Ankara said the decision was up to the courts.More news: Richarlison strikes twice but 10-man Everton held at Wolves
Turkey is a major emerging market economy with $466 billion in foreign debt (about 78 percent in USA dollars and about 18 percent in euros), or 52.9 percent of gross domestic product. Financial upheaval there risks further destabilizing an already volatile region.
He also blamed those seeking higher interest rates to help cope with the lira's record losses as being behind the country's economic misfortunes.
Ash continued: "I don't think you can understate the geopolitical significance".
To add to Turkey's problems, US State Department introduced sanctions after the former detained an American evangelical pastor.
His tone echoed that of a speech given on Thursday when he told supporters that "if they have dollars, we have our people, our righteousness, and our God". On Friday, he said the country had to take steps in answer "to those who have waged an economic war against us".
"I'm not aware of any prior administration using tariffs in this way, and there's a very simple reason: because they're an incredibly blunt instrument that often can have blowback on American workers and consumers as we've seen in the China context", said Ned Price, a former Central Intelligence Agency officer who also served as a National Security Council spokesman during the Obama administration.
He also repeated his call to Turks to sell their dollar and euro savings to shore up the lira.More news: NASA's $2 billion flight to sun delayed by last-minute technical problem
He added: "If there are dollars under your pillow, take these out".
"The markets have lost confidence in the triumvirate of President Erdogan, his son-in-law as finance minister and the Turkish Central Bank's ability to act as it needs to", said Charles Robertson, global chief economist at Renaissance Capital.
Erdogan also warned that Ankara could start looking for "new friends and allies".
"Our relations with Turkey are not good at this time!" hewrote".
The US responded by imposing sanctions on Turkey and threatening more. It is host to an X-band radar, a critical part of the Western alliance's missile defence system again Iran.
In the worst case scenario of the collapse of a European bank, there could be "contagion" - other countries and banks, including those in Britain, may be imperilled - raising the spectre of the economic turmoil that followed the 2008 global banking crisis.
Timothy Ash, senior emerging markets strategist at Bluebay Asset Management told CNBC that Brunson's detention proves how valuable the Christian vote is in America.More news: Ford unveils 2019 NASCAR Mustang