Donald Trump has said he will announce his choice for a running mate this week, in advance of the start of the Republican National Convention on Monday.
Here is a look at one of the four men most likely to join Trump as a vice presidential candidate – Mike Flynn.
Mike Flynn
In August 2014, Flynn left his job at the Defense Intelligence Agency, allegedly after clashing with officials in the Obama White House.
Age: 57
Flynn is more to the left than others being considered for the job of Trump's running mate. When asked about same-sex marriage, Flynn said, "What people do in their private lives, these are not big issues that our country’s dealing with."
What they are saying about Flynn
Flynn is a Democrat
National security chops
The Associated Press contributed to this report.