He met with Alaska's then-Gov. Sarah Palin in 2008, and Mitt Romney reportedly spoke by phone with Kissinger during the 2012 campaign.
Trump has lately featured foreign policy issues more prominently in his campaign, delivering a speech on his proposed "America first" ideology in April. He named five foreign policy advisers to his campaign in March, though it is unclear how often he consults with the men. Kissinger was not on the list.