Scott Kelly, a retired American astronaut with multiple space flights under his belt, apologized Sunday after quoting Winston Churchill and calling the 20th century British prime minister "one of the greatest leaders of modern times."

"Did not mean to offend by quoting Churchill. My apologies. I will go and educate myself further on his atrocities, racist views which I do not support. My point was we need to come together as one nation. We are all Americans. That should transcend partisan politics," Kelly wrote on Twitter in the evening.

Eight hours prior, in a tweet that has not been deleted as of press time, Kelly cited Churchill to lament the current state of affairs.

"One of the greatest leaders of modern times, Sir Winston Churchill said, 'in victory, magnanimity.' I guess those days are over," Kelly tweeted.

Some Twitter users reacted to Kelly offering an apology, telling him he overreacted to what appeared to be a wave of online trolls.

While Churchill, who died in 1965, is often viewed as a successful wartime leader who helped lead the United Kingdom and its allies to victory against Nazi Germany and the Axis, he is also commonly criticized for his attitudes on race and colonialism.