Retired Vice Adm. Robert Harward has turned down President Trump’s offer to become his new national security adviser, according to two people with knowledge of the decision.

Harward would have replaced Michael Flynn, who announced his resignation late Monday amid allegations that he discussed U.S. sanctions with a Russian official before Trump took office and then misrepresented the content of that conversation to Vice President Pence and other administration officials.

One factor in Harward’s decision was that he couldn’t get a guarantee that he could select his own staff, according to a person close to Trump with knowledge of the discussions.