Federal Reserve Chair Jerome Powell has asked the U.S. central bank's inspector general to review the costs involved in the renovation of its historic headquarters in Washington, as Trump administration officials intensify their criticism of how the Fed is being run.

National Economic Council Director Kevin Hassett said Sunday that the president’s authority to fire Federal Reserve Chair Jerome Powell was “being looked into.”Asked in an interview on ABC News’ “This Week” whether he believes President Donald Trump has the authority to fire Powell,

The move comes amid speculation that Trump, who has clashed with Powell over interest rates, might try to use the project to remove the Fed chief “for cause."

The European Union has warned that its trade with the United States could be effectively wiped out if Washington makes good on its threat to slap a 30% tariff on goods imported from the bloc.

U.S. stock futures fell Sunday, a day after President Donald Trump threatened to impose new 30% tariffs against imports from Mexico and the European Union.