WASHINGTON (AP) — President Joe Biden has directed the U.S. Secret Service to protect independent presidential candidate Robert F. Kennedy Jr., after the attempted assassination of Donald Trump, the Homeland Security secretary said Monday.

Kennedy is a longshot to win Electoral College votes, much less the presidency. But his campaign events have drawn large crowds of supporters and people interested in his message.

"Thank you, President Biden, for extending me Secret Service protection," Kennedy said in a statement. He also thanked his private security firm, Gavin de Becker & Associates "for keeping me safe for the past 15 months of my presidential campaign."

Homeland Security Secretary Alejandro Mayorkas said Biden had directed the protection for Kennedy "both prior to and after the events of this past weekend."

The Secret Service is legally required to protect major party presidential and vice presidential candidates and their families 120 days out from a general election, but third-party candidates are treated on an as-needed basis.

The Department of Homeland Security acknowledged in its 2024 budget overview that recent requests for candidate protection were coming in earlier than in the past.

Threats to political candidates are common, but law enforcement officials have said that there has been an uptick in violent rhetoric since the weekend attack at the Trump rally. Mayorkas said both Biden and Trump are "constantly the subject of threats."

"We are in a heightened and very dynamic threat environment," he said.

With a famous name and a loyal base, Kennedy has the potential to do better than any third-party presidential candidate since Ross Perot in the 1990s. But he didn't participate in the first presidential debate on June 27. Both the Biden and Trump campaigns, who fear he could be a spoiler, bypassed the nonpartisan debate commission and agreed to a schedule that essentially left out Kennedy.

Kennedy, who last year challenged Biden for the Democratic nomination before launching an independent bid, has argued that his relatively strong showing in a few national polls gives his candidacy heft. Polls during the 2016 presidential campaign regularly put libertarian Gary Johnson's support in the high single or low double digits, but he ultimately received only about 3% of the vote nationwide.

Trump became the official Republican presidential nominee on Monday after receiving the votes of enough delegates at the Republican National Convention. He was not seriously injured in the shooting over the weekend in Pennsylvania. There is an independent review of the attack.

Mayorkas said Trump's protection has been enhanced based on the "evolving nature of the threats to the former president" and his shift from presumptive nominee to nominee.