Donald Trump Says Country Owes Jimmy Carter A 'Debt of Gratitude'

Donald Trump's showering praise on the late Jimmy Carter ... saying he did his best to improve the lives of his fellow Americans -- and, the country owes him a debt.

The president-elect posted to his social media platform, Truth Social, Sunday ... only about an hour after the Carter Center announced the former president had passed away at 100.

In his message, Trump writes that anyone who has been president knows it's a very exclusive club ... and, only members in its ranks can understand the responsibility of leading the country.

DJT says JC faced numerous issues when he was president ... and, he did everything he could to "improve the lives of all Americans. For that, we all owe him a debt of gratitude."

Trump says he and his wife Melania are thinking of the Carter family at this difficult time ... and, he urges his followers to keep them in their prayers.

It's a stark change to Trump and Carter's relationship while the latter was still alive ... just two months ago, on Carter's 100th birthday, Trump called Joe Biden the worst president ever -- before saying Jimmy was "the happiest man because Carter is considered a brilliant president by comparison.”

Carter passed away surrounded by family Sunday night after spenging nearly two years in hospice care. His wife, Rosalynn Carter, passed away last year at the age of 96.

Tributes from all over the political world are pouring in for Carter ... including from President Joe Biden who called him an "extradordinary leader" and former president Barack Obama who wrote Jimmy taught the world "what it means to live a life of grace, dignity, justice, and service."