President Obama this week nominated top White House Iran advisor Puneet Talwar to be Assistant Secretary of State for Political Military Affairs, as the Back Channel reported in July was expected.

The promotion for Talwar, who has served since 2009 as the National Security Council Senior Director for Iran, Iraq and the Persian Gulf affairs, would mark the latest departure of a key member of the US Iran negotiating team as the US prepares to resume P5+1 nuclear talks with the new Iranian Hassan Rouhani administration in the coming weeks, after a five month hiatus.

Rob Malley, a former Clinton administration NSC Middle East advisor, is expected to join the NSC, succeeding Talwar after his confirmation, as the Back Channel previously reported was under consideration. The White House declined to comment. Malley didn’t respond to a query.

But several sources suggested that Malley may not play the same role on Iran issues as Talwar, and that National Security Advisor Susan Rice would like to bring Malley to the White House to help rethink how the National Security Staff Middle East work is organized. Malley has already been informally advising the State Department on Syria from the outside, officials tell the Back Channel.