US Treasury Secretary Steven Mnuchin has announced that the steps ordered by Congress for sanctions against Russia will be imposed in coming weeks.

In testimony before a House subcommittee on Tuesday, Mnuchin pushed back against the idea that US President Donald Trump is trying to block the sanctions in response to Russia's alleged meddling in the 2016 US presidential election, saying Trump is "fully supportive."

"We will implement them," Mnuchin said. "I expect in next several weeks we'll be going forward with sanctions on Russia."

Trump has come under from both Republicans and Democrats in Congress, which nearly unanimously passed a new sanctions bill against Russia last summer, for not punishing Russia enough.

The Trump administration announced in January it was not going to announce sanctions against Russia under the new law.

Mnuchin assured the legislators that "in recent conversations with the president he is fully supportive of the work we are doing," and that the sanctions will be enforced.

A senior US administration official had also said the White House has warned governments around the world that they could face sanctions for "significant transactions" with the Russian military.

Last month, the US Justice Department's Special Counsel Robert Mueller, who is investigating the alleged Russian meddling, indicted 13 Russian nationals and three Russian entities accused of interfering in elections in the US as part of what is called a conspiracy to support Trump and disparage Hillary Clinton.

President Trump himself has repeatedly told Americans that the allegations of collusion between his campaign and Russia were not true. Back on February 16, shortly after the publication of Mueller’s lengthy report, he said that “the results of the election were not impacted.”