WASHINGTON (Reuters] – The United States and Russia continue to work together on the Iran nuclear accord, a high-ranking official from the State Department said Tuesday. This was in response to the suggestion that Moscow could now see the importance of sanctions against Ukraine not affecting the agreement’s execution.

Washington will not approve Russian participation in any nuclear projects included in the Joint Comprehensive Plan of Action (JCPOA) once it has been fully implemented. The official spoke on condition of anonymity.

Following talks with Hossein Amirabdollahian from Tehran, Sergei Lavrov, Russian Foreign Minister, said that U.S. allegations suggesting Moscow had blocked efforts to restart the Iran nuclear accord were not true.

Lavrov stated that Russia received assurances from the U.S. in writing, that the sanctions against Moscow regarding Ukraine wouldn’t hinder cooperation within the context of the agreement. This deal lifted the sanctions on Tehran and imposed limits on Iran’s nuclear program.

The senior U.S. State Department official, when asked questions about Lavrov’s statements, stated “We continue engaging with Russia on full implementation of JCPOA.” Russian participation to nuclear projects as part of fully implementing the JCPOA would be sanitized.

“We cannot provide assurances beyond that to Russia and have no comment on (Foreign Minister) Lavrov’s publicly reported remarks,” the official added. Moscow may now know that the Russia-related new sanctions have no connection to the JCPOA, which is what we’ve publicly stated. They should have no impact on the implementation of the JCPOA.