White House press secretary Sarah Sanders said in a statement on Monday that the administration is "considering additional sanctions on Russian Federation, and a decision will be made in the near future".
The United States also imposed sanctions on 24 Russians earlier this month over what USA intelligence agencies have said was interference in the US presidential election.
That message appeared to tap the breaks on imminent punitive economic measures. "We convinced him to remain", he said.
Nikki Haley, the US Ambassador to the United Nations, indicated the sanctions would be aimed at sending a message to Russian Federation, which she said has blocked six attempts by the UN Security Council to make it easier to investigate the use of chemical weapons.
US Ambassador to the United Nations Nikki Haley arrives for a UN Security Council meeting, at United Nations Headquarters in NY, on April 14, 2018.
Haley made the remarks in an interview on CBS, saying the Treasury Department would announce the new sanctions and insisted the US has sent "a strong message" about the use of chemical weapons. She said that the U.S. Treasury secretary "will be announcing those on Monday, if he hasn't already".
It is not clear what has caused the apparent delay, but sanctions decisions are usually weeks if not months in the making.
Trump last week tweeted that U.S. relations with Russia were at their lowest point since the Cold War - and put the blame at the feet of special counsel Robert Mueller and his investigation into Russian election meddling and possible collusion with the president's campaign.
US President Donald Trump steps off Air Force One upon arrival at Palm Beach International Airport in West Palm Beach, Florida on April 16, 2018.
"The president is going to continue to be tough on [Russia]", she said.
"But that's going to depend on the actions of Russian Federation. But at the same time, he'd still like to have a good relationship with them".
The White House said US troops will remain in Syria, for now, but the end-goal is still to pull out of the country.
"Secondly, we want to make sure that they understand that ISIS [ISIS] has to be defeated completely and wholly in a way that we know that we have stabilized the region".