Clinton and Lynch met privately at Phoenix airport

The exchange comes as the FBI is investigating the potential mishandling of sensitive information that passed through the server Clinton, the presumptive Democratic nominee, used for personal and government correspondence as secretary of state.

Republicans have called for an independent prosecutor, saying the Justice Department under a Democratic president should not be investigating a Democratic presidential candidate.

The matter was referred for investigation last July by the inspectors general for the State Department and intelligence community following the discovery of emails that they said contained classified information.