"The signing by the US President of a new sanctions law against Russia creates several consequences: firstly, the hope of improving our relations with the new US administration is dead. Secondly, US declared a fully-fledged trade war on Russia. Thirdly, the Trump administration demonstrated complete impotence by humiliatingly transferring executive powers to the Congress, which changes the balance of power in US political circles," Medvedev wrote in his Facebook blog.
Medvedev predicted that the sanctions will be in force for decades to come, causing tensions between Moscow and Washington.
The prime minister stressed that Trump has been completely overplayed by the US establishment, predicting that the US president will be ousted.
President Donald Trump has signed a bill to slap new sanctions on Russia, Iran and North Korea on Wednesday morning. He signed the bill on Wednesday morning, without holding an official signing ceremony as he has done with other major pieces of legislation, according to media reports.
The law also limits the US president's ability to ease any sanctions on Russia by requiring Congress' approval to lift any restrictions.
For instance, Trump would now need Congress' permission to reverse measures imposed by his predecessor Barack Obama. He would also need lawmakers' approval to return Russian diplomatic properties that were seized under the previous administration.