The White House said the president had nominated Stuart Jones, the incumbent ambassador to Jordan, to fill in the vacancy in Iraq left by Robert Stephen Beecroft.
Beecroft, a career diplomat, has been posted in Iraq since 2012. He served as ambassador to Jordan from 2008 to 2011.
Anne Patterson, US last ambassador to Egypt, was nominated as the assistant secretary of state for Near Eastern affairs in August 2013.
The Obama administration decided to relax a partial suspension of aid to Egypt recently, imposed after the Egyptian military removed the then president, Mohamed Morsi, from power in July last year and started a crackdown on protesters.