Former President Donald Trump on Monday blamed a polarized political environment and "rhetoric" from Vice President Kamala Harris and President Joe Biden for the second assassination attempt on his life over the weekend -- though both gunmen's motives remain unclear.

He said that things Harris and Biden said caused the suspected gunman Ryan Wesley Routh to act on Sunday.

"He believed the rhetoric of Biden and Harris, and he acted on it," Trump said of the gunman in an interview with Fox News Digital. "Their rhetoric is causing me to be shot at, when I am the one who is going to save the country, and they are the ones that are destroying the country -- both from the inside and out."

The suspect's motive remains unknown as the FBI continues to conduct an extensive investigation into Routh's background, looking at whether Routh was frustrated with Trump's position on Ukraine, sources tell ABC News.

The FBI is investigating Sunday's incident as an "attempted assassination." It was not clear if Routh was aiming his gun at the former president and it's not clear if Routh fired a shot. Agents fired at the suspect after spotting his rifle through the fence line near the Trump International golf course, multiple sources told ABC News.

Routh appeared in a federal courtroom in West Palm Beach Monday morning and faces two firearm-related charges.

While blaming Democrats for using "highly inflammatory language," the former president himself also attacked his opponents, calling them enemies and threats.

"These are people that want to destroy our country," Trump said. "It is called the enemy from within. They are the real threat."

Harris' campaign said it would not be commenting on Trump's comments at this time.

The political nature of his comments is a departure from Trump's immediate response following his assassination attempt earlier this summer in Butler, Pennsylvania.

After the shooting, Trump called for political unity, initially urging his allies not to point blame across the aisle.

"In this moment, it is more important than ever that we stand United, and show our True Character as Americans, remaining Strong and Determined, and not allowing Evil to Win," Trump had written.

His tone later shifted, falsely suggesting during the ABC News presidential debate that he "probably took a bullet to the head" because of Harris. The FBI has not established a motive that explains why Thomas Matthew Crooks fired on Trump.

It is not clear what motivated the suspected gunman in Pennsylvania, Thomas Matthew Crooks, to shoot at the former president.

On Sunday, Secret Service agents fired at Routh, who was armed with an AK-47-style rifle near the Trump International golf course in West Palm Beach, Florida.

Speaking to reporters on Monday, Biden called for more Secret Service assistance.

"One thing I want to make clear, the [Secret] Service needs more help and I think the Congress should respond to their needs, if in fact they need more servicemen," Biden said while departing the White House.