Trump's threat against Russia runs parallel to a Senate-led effort to pass crippling sanctions on countries that buy Russian energy.

The legislation, which would allow the president to levy a 500% tariff on imports from countries that purchase Russian uranium, gas and oil, has gained momentum in the Senate as Trump has signaled he will escalate US action against Russia.

Ask the Senate majority leader why he is not bringing it to the floor,” said Sen. Elizabeth Warren. “Is he afraid of Donald Trump?”