A photo captured a fist-pumping President Donald Trump as he arrived in Pennsylvania on Tuesday to attend a memorial service on the anniversary of the 9/11 terrorist attacks.

The image went viral on Twitter as some people criticized Trump's demeanor ahead of the memorial service.

Trump has frequently been criticized for his behavior toward tragic events, including the September 11 attacks.

A photo on Tuesday captured a fist-pumping President Donald Trump arriving in Pennsylvania to attend a memorial service on the anniversary of the 9/11 terrorist attacks, prompting outrage on social media over the president's demeanor.

The image went viral on Twitter, as some people criticized Trump's expression ahead of the memorial service.

Here are some of the reactions:

Trump has frequently been criticized for his behavior toward tragic events, particularly the September 11 attacks.

On the day of the attacks, he told reporters on-air that he had the tallest building in Manhattan after the World Trade Center collapsed, a comment for which Trump still faces backlash from people who say he was bragging.

During his 2016 presidential campaign, Trump said he saw that thousands of Muslims in New Jersey were cheering about the attacks as they heard the news, a claim that has been thoroughly debunked.

"I watched when the World Trade Center came tumbling down, and I watched in Jersey City, New Jersey, where thousands and thousands of people were cheering as that building was coming down," Trump said at the time. "Thousands of people were cheering."

On Tuesday, Trump marked the anniversary of the attacks by tweeting, "17 years since September 11th!"