Former vice president Joe Biden couldn’t comprehend why President Trump would consider an invitation from Russian President Vladimir Putin to celebrate the two countries ending World War II 75 years ago.

Putin invited Trump to attend the May 9, 2020 Victory Day parade in Moscow to celebrate the 1945 allied victory over Nazi Germany, an anniversary the president described as “a very big deal,” the Associated Press reports.

Trump said the event is “right in the middle of political season,” but he “would love to go if I could.”

Biden was unaware and flabbergasted when questioned by a reporter about the invite at a campaign event in New Hampshire on Friday.

“Do you have any idea of President Trump going to Moscow for the Victory Day Parade?” a CNN reporter asked the Democrat frontrunner as he signed autographs for supporters.

“Are you serious?” Biden replied, clearly shocked.

“He’s been invited and he’s considering it,” the reporter said.

“You’re kidding me,” Biden said as he looked around and a staffer handed him a bowl of chili. “Whoa.”

Another reporter asked a question about his son Hunter’s shady overseas business deals, but the 76-year-old career politician ignored the question, still reeling from the big news.

“Are you joking?” Biden asked the CNN reporter.

“No,” the reporter said.

Biden offered dismissive hand gesture as he was ushered to a nearby building, shaking his head.

The former vice president was in Concord to formally declare his candidacy by handing over a $1,000 check to Secretary of State Bill Gardner. Biden made a spectacle out of the simple affair with Gov. John Lynch and International Association of Fire Fighters President Harold Schaitberger by his side, along with hundreds of supporters crammed into the Statehouse, WMUR reports.

At the event, Biden touted polling that puts him in the lead among 2020 candidates and pushed back against criticism his campaign is in trouble.

“The last polls I looked at, I’m pretty far ahead,” Biden bragged.

In “states that we have to win back” that Trump won over Democrat Hillary Clinton in 2016, “if I’m not mistaken, I’m doing pretty well relative to Trump and relative to all the people running in the Democratic primary,” he said.

Biden told reporters he’s in it to “plan on trying to win” it.

“This is a marathon, and it’s really important that you do well in the first four states,” he said. “It could be enough to make you a nominee. It could be enough to keep you in the race. It could be enough to take you out of the race.

“I plan on trying to win New Hampshire,” Biden said. “I’m not here to come in second. I never enter anything to come in second.”