The Obama administration on Sept. 17 officially named outgoing US Ambassador to Poland Stephen D. Mull the lead coordinator for Iran nuclear implementation, as a congressional deadline to block the deal ran out with no disapproval measure ever reaching President Barack Obama’s desk.

“I have always said that, as important as it was to negotiate the nuclear deal with Iran, implementing it was going to be even more crucial in meeting our national security objectives,” Secretary of State John Kerry said in a statement announcing Mull’s appointment.

“As we move past the 60-day Congressional review period, it is vitally important that we now have the right team with the right leader in place to ensure the successful implementation of the Joint Comprehensive Plan of Action (JCPOA),” Kerry said. “Steve Mull is absolutely the right person to lead this effort.”

A 33-year veteran foreign service officer, Mull previously served as executive secretary of the State Department (2010-12), ambassador to Lithuania and, most critically, as senior adviser to then-Undersecretary of State William Burns (2008-10) when Burns was the lead US Iran nuclear negotiator and the United States was helping negotiate UN Security Council Resolution 1929 that sanctioned Iran over its nuclear program, among previous relevant assignments, Al-Monitor reported Sept. 16 in anticipation of his appointment.