President Biden condemned the shooting at the Trump rally and called on other Americans to do the same.

"The idea that there's political violence or violence in America like this, is just unheard of. It’s just not appropriate," he said at a news conference.

Biden said he was trying to get ahold of Trump, who he called Donald, on the phone and wanted to talk to him.

"There is no place in America for this violence. It's sick," he said.

Security is being increased across New York City following a possible assassination attempt on former President Donald Trump, officials said.

Out of an abundance of caution, the NYPD is increasing its presence across the city, including at Trump Tower, 40 Wall Street, Foley Square and City Hall.

There is no threat or connection to New York City at this time.

"Whatever your politics, we should all be able to agree that violence is wrong and we should be able to disagree peacefully," Mayor Eric Adams said in a statement.

The Biden campaign said it will halt all ads for the presidential race.

"The Biden campaign is pausing all outbound communications and working to pull down our television ads as quickly as possible," a campaign spokesman said.

-ABC News' Gabriella Abdul-Hakim

The White House announced that Biden will shortly deliver remarks with regards to the shooting at the Trump rally in Pennsylvania.