Russia Prime Minister: new US sanctions amount to 'full-scale trade war'

New sanctions on Russia which U.S. President Donald Trump has signed into law are tantamount to a "full-scale trade war", Russian Prime Minister Dmitry Medvedev said on Wednesday.

Medvedev also said in a Facebook post that the sanctions showed the Trump administration was utterly powerless.

"The hope that our relations with the new American administration would improve is finished," he wrote.

(Reporting by Alexander Winning and Jack Stubbs; Editing by Louise Ireland)