WASHINGTON (AP) — President Donald Trump says Russian President Vladimir Putin made an "incredible offer" of law enforcement collaboration during the leaders' one-on-one summit.

Trump told reporters Monday that Putin said American investigators who have charged 12 Russian hackers with hacking the 2016 presidential election can come work with Russian investigators on the case.

Trump called that an "incredible offer."

A spokesman for special counsel Robert Mueller, whose office on Friday charged the hackers, declined to comment.

It was not clear from Trump's statement what sort of help Putin was offering. The United States does not have an extradition treaty with Russia, making it uncertain that the indicted Russian military intelligence officers will ever be prosecuted in an American courtroom.