President Donald Trump said in a tweet Friday he authorized doubling existing tariffs on steel and aluminum imports from Turkey, after the Turkish lira USDTRY, +0.19% dropped more than 10%. Levies on aluminum would be 20% and steel 50%, per the tweet. Trump previously had called out trade partners' weak currencies versus the strong greenback, openly favoring a weaker U.S. currency. U.S.-Turkish relations have been rocky of late over the detention of a U.S. pastor by Turkish authorities. One dollar last bought 6.2826 lira, up 13.3% from Thursday, a fresh historic low, according to FactSet.