The comments were "clearly" racist, Kalondo said, but stressed the U.S. was "much stronger than the sum total of one man".
Trump also denied saying "anything derogatory about Haitians other than Haiti is, obviously, a very poor and troubled country".
"Given the historical reality of how many Africans arrived in the United States as slaves, this statement flies in the face of all accepted behaviour and practice", AU spokeswoman Ebba Kalondo told the Associated Press news agency.
They quickly sparked anger among Democrats and Republicans and revived questions about Trump's tendency to make racially charged remarks. Among those attendees was the nephew of the late civil rights In icon Isaac Newton Farris, Jr.
Ignoring shouted questions about the mounting firestorm over race, the president paid tribute during a ceremony to the reverend's "peaceful crusade for justice and equality".
The Senate group has been working for months to craft legislation that would protect 700,000 children who were brought to the United States as illegal immigrants and later given protection from deportation under a programme known as Deferred Action for Childhood Arrivals, or DACA. I have a wonderful relationship with Haitians.
Trump said on Twitter on Friday he merely used "tough" language when discussing a new immigration bill with a group of US senators.
Duncan, R-3rd District and chairman of the House Foreign Affairs Committee's Subcommittee on the Western Hemisphere, has long supported the island nation's recovery from a devastating 2010 natural disaster, but has also called for more transparency in US aid money sent to the country.
House Democratic Whip Steny Hoyer of Maryland said, "President Trump's comments are racist and a disgrace".
The ceremony was attended by a number of King's descendants as well as a frighteningly large number of miscellaneous Black people.
President Donald Trump's vulgar remark disparaging Haitians and African countries didn't surprise a local scholar who teaches at Winston-Salem State University.
Botswana summoned the USA ambassador to the country to "clarify if Botswana is regarded as a "shithole" country", according to a foreign ministry statement calling Trump's comments "irresponsible, reprehensible and racist".
In 2009 Trump's predecessor, Barack Obama, chose Ghana's capital Accra to set out his foreign policy goals for Africa in a speech in which he said he saw Africa "as a fundamental part of our interconnected world".
"Sir, they're not shithole countries".
In Geneva, UN human rights spokesman Rupert Colville said: "These are shocking and shameful comments from the president of the United States". So it seems to me that if you can control who gets a job you've gone a long way in controlling illegal immigration.
Some in Africa chose to own Trump's vulgar language or throw it back in his face. He also blamed "both sides" after a white supremacist rally in Charlottesville, Virginia, turned violent.
"Mr Trump may say what he pleases, but I am proud of being Haitian".
"We have seven days and the clock is ticking".