Story highlights Trump and Obama haven't spoken in a year

The last time they spoke, Trump and Obama were standing on the East Front of the US Capitol on Inauguration Day

Ties between presidents -- if not always friendly -- are usually at least existent. That Trump and Obama have avoided each other speaks to the unprecedented nature of the current White House, and the lingering animosity between two men who openly sparred during 2016's presidential campaign.

Trump hasn't shied away from blasting decisions Obama made during his tenure, and has steadily chipped away at key pieces of Obama's legacy like the Paris climate accord and the Affordable Care Act. He's also launched personal attacks , falsely claiming that Obama ordered the phones tapped at Trump Tower or that Obama failed to call family members of slain US servicemen.

Obama, meanwhile, has reserved his criticism of Trump for policy matters . On the rare occasions he's spoken publicly over the past year, he's made only veiled references to the current Oval Office occupant.

The last time they spoke, Trump and Obama were standing on the East Front of the US Capitol as an idling military helicopter stood nearby. Moments after Trump was inaugurated, Obama appeared loose and smiling, his post-presidency life about to begin.

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