Trump spokesman Katrina Pierson said he his looking forward to a general election match-up.
Democrats polled in New Jersey say having Booker on the ticket won't help Clinton.
The state votes on June 7.
Trump has said he would cut funding for the EPA if elected.
Trump said he plans to announce his running mate in July.
Mario Trujillo 05/04/16 11:58 AM EDT
The app lets the public upload video to the GOP group.
Kasich will make a statement about his campaign at 5 p.m. on Wednesday.
DULLES, Va. — The Ohio governor now plans an "announcement" at 5 p.m.
The new web ad follows a $2 million TV and digital ad buy in Wisconsin earlier this week.
Trump defended his claim that Ted Cruz's father was linked to Lee Harvey Oswald.