This was stated by Deputy Spokesperson for the US Department of State Vedant Patel during a briefing.
"We believe Russia to already be in violation of the New START Treaty, but broadly, the U.S. is going to continue to evaluate next steps with regard to Russia’s noncompliance with New START. And we’ll consider additional countermeasures," he said.
According to Patel, compliance with the New START Treaty is an important obligation of all parties.
"That's why we continue to do what we can to try and bring all parties back into compliance," he added.
On February 28, Russian President Vladimir Putin signed a decree to temporarily suspend Russia's participation in the Strategic Arms Reduction Treaty.
At the time, the U.S. State Department emphasized that Russia's announced suspension of participation in the New START Treaty was legally invalid.
Subsequently, the United States announced that it would not share data under the key nuclear arms control agreement after Russia said it would not do so.