Twitter user Harold Isaac shared idyllic-looking pictures of his country alongside the following comments: "Hey #ShitHolePresident! Here is what my #shithole looks like."
Haiti's U.S. ambassador condemned the statements in more diplomatic terms.
"In the spirit of the people of Haiti we feel in the statements, if they were made, the president was either misinformed or miseducated about Haiti and its people," Paul G. Altidor said in a statement.
Rupert Colville, a human rights spokesman for the international organization, said: "If confirmed these are shocking and shameful comments from the president of the United States, I'm sorry but there is no other word for this but racist."
"You cannot dismiss entire countries and continents as 'shitholes,' whose entire populations, who are not white, are therefore not welcome," he said in Geneva.
The 55-member continental organization that works for greater economic and political unity and solidarity across Africa said it was "frankly alarmed" by Trump's comments.
"Given the historical reality of how many Africans arrived in the United States as slaves, this statement flies in the face of all accepted behavior and practice," African Union spokeswoman Ebba Kalondo said in a statement. "This is particularly surprising as the United States of America remains a global example of how migration gave birth to a nation built on strong values of diversity and opportunity."
Boniface Mwangi, a social activist, tweeted that Africa "isn’t a shithole."
"How America elected a narcissist, racist, white supremacist to be their president defies logic. Africa sends love and light to America. #ShitholeTrump," he said.
Leanne Manas, a television anchor for the South African Broadcasting Corporation, tweeted: "Good morning from the greatest most beautiful 'shithole country' in the world!!!" Many South Africans expressed solidarity with her ironic comments.
"The Daily Show" tweeted of its South African-born host, Trevor Noah: "As someone from South Shithole, Trevor is deeply offended by the president's remarks."
Vincente Fox, Mexico's former president and a longtime Trump social media troll, was particularly blunt in his assessment of Trump's vulgarity.
"Your mouth is the foulest shithole in the world. With what authority do you proclaim who's welcome in America and who's not. America's greatness is built on diversity, or have you forgotten your immigrant background, Donald?" he said.
The French gave a very French reaction.
Government spokesman Benjamin Grivaux told reporters after a Cabinet meeting that "silence" was preferable to any reaction in response to Trump’s vulgar comments.
"We must keep a correct language especially when we speak about countries that sometimes suffered from bad weather, a great poverty and that are in a great distress."