Republican Lindsey Graham getting ready to throw his hat into the 2016 presidential race .
The South Carolina Senator saying Monday he will announce his decision on whether to run for president on June 1.
Graham has been a vocal critic of President Barack Obama's foreign policy, and has stood out from other GOP candidates by defending former president George W Bush's decision to invade Iraq.
Graham would become the seventh Republican to announce his candidacy for the 2016 nomination, joining fellow senators Ted Cruz, Rand Paul & Marco Rubio.
Former Arkansas governor Mike Huckabee, ex Hewlett Packard chief Carly Fiorina and retired physician Ben Carson are also in the race.