WASHINGTON (AP) — The U.S. appears poised to lift at least some sanctions against Iran -- possibly as early as January.

Secretary of State John Kerry says in a letter to the Senate Foreign Relations Committee that Iran is fulfilling its obligations under the agreement in what Kerry calls a "transparent" and "verifiable" way, and that "suspension of sanctions ... is appropriate."

The Associated Press obtained a copy of the letter.

The letter also says Iran hasn't engaged in covert activities that could significantly advance its nuclear weapons program.

The committee's top Democrat, Maryland Sen. Ben Cardin, said at a hearing Thursday that it appears that sanctions relief could start as early as January, not in the spring as first expected.