Story highlights Trump has become more open in his criticism of the President

Obama has also offered criticism of his successor, albeit more tacitly

Palm Beach, Florida (CNN) Separated by the entire North American continent and half the Pacific Ocean, the incoming and outgoing presidents are trading barbs -- both veiled and overt -- from their respective holiday vacations, souring a once a collegial public relationship.

Marked by insults on Twitter, perceived public slights and foreign policy disputes, the ties between President-elect Donald Trump and President Barack Obama have significantly frayed less than a month before Trump is sworn into office.

Both sides say the actual mechanics of transferring power from one administration to another are proceeding smoothly. The President-elect said he spoke with Obama Wednesday in what he termed a "nice conversation." And Trump's spokesman said Wednesday he expected more conversations between the two men before Inauguration Day on January 20.

Trump, however, has become more open in his criticism of the President since he won last month, arguing on Twitter that Obama misjudged the election and lost badly. He scaled up his disparagement on Wednesday, writing that "inflammatory" statements from Obama were hampering a smooth transition.

Obama has also offered criticism of his successor, albeit more tacitly. During a historic speech Tuesday in Pearl Harbor alongside Japanese Prime Minister Shinzo Abe, Obama cautioned against tribalism and isolationism -- warnings that, during the campaign, he used to argue against Trump's candidacy.

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