Wally Adeyemo, President Joe Biden's nominee as deputy Treasury secretary, underscored his commitment to rigorous enforcement of U.S. sanctions against Iran, Russia and other countries.
In written responses to queries from members of the Senate Finance Committee, Adeyemo said Iran should only enjoy sanctions relief if it resumes compliance with the 2015 nuclear accord.
He said Treasury would look carefully at "any Iranian efforts to evade sanctions and abuse the international banking system" to fund terrorist activities.
"Iran’s support for terrorism is a very serious concern and, if confirmed, I will work with colleagues at Treasury to closely monitor and seek to disrupt that support with all available tools," Adeyemo said in responses viewed by Reuters.
The Senate Finance Committee is slated to vote on Adeyemo's nomination on Wednesday, paving the way for a floor vote by the full Senate in coming weeks.
Iran on Sunday ruled out holding an informal meeting with the United States and other major powers to discuss ways to salvage the unraveling 2015 nuclear deal, insisting Washington must first lift all its unilateral sanctions.
The United States said it was disappointed but remained ready to "re-engage in meaningful diplomacy" and would consult with the other major powers to seek a way forward.
The Biden administration has said it is ready to talk to Iran about both nations resuming compliance with the accord, which scrapped broad economic sanctions against Iran in return for curbs intended to prevent it from acquiring nuclear weapons - something Iran says it does not want.
Adeyemo also underscored his commitment to enforce sanctions targeting Russian actors, and said he would work closely with other U.S. officials to implement laws that mandate sanctions on companies and individuals involved with the Nord Stream 2 pipeline being built from Russia to Germany.