FILE PHOTO: Signage is seen at the headquarters of the Federal Communications Commission in Washington, D.C., U.S., August 29, 2020. REUTERS/Andrew Kelly/File Photo Reuters WASHINGTON (Reuters) – China Telecom's U.S. subsidiary on Monday asked a U.S. appeals court to block the decision of the Federal Communications Commission to revoke the telecommunication company's authorization to operate in the United States. China Telecom Americas was ordered by the FCC to discontinue U.S. services by early January after the U.S. regulator cited national security concerns. The Chinese telecom company told the U.S. Appeals Court for the District of Columbia on Monday it must…