Brooks Koepka believes he can claim 10 or more major titles and feels golf's biggest events are "sometimes the easiest ones to win" as he prepares to defend his US PGA Championship crown.

The U.S. Open champion of 2017 and 2018, Koepka also won last year's PGA at Bellerive and has developed a reputation for delivering his very best form when it matters most.

In a pre-tournament news conference at Bethpage on Tuesday, the 29-year-old American was asked if he had targeted a specific number of major wins in his career.

"Yeah, I've got a number," Koepka replied. "I don't see why you can't get to double digits.

"I think sometimes the majors are the easiest ones to win. Half the people shoot themselves out of it, and mentally I know I can beat most of them, and then from there it's those guys left, who's going to play good and who can win. I don't see any reason it can't get to double digits."

Tiger Woods (15) is the only active golfer with more than five triumphs in majors.

"I kind of dummy it down and make it very simple, and I think that's what helps me," said Koepka as he explained the method that has helped him to three wins in quick succession.

Koepka will play the first two rounds at Bethpage alongside Open champion Francesco Molinari and a resurgent Woods, who famously won the Masters last month.

While the 43-year-old Woods beat Koepka into second place at Augusta, the roles were reversed at Bellerive last August.

Asked whether he felt like a rivalry was developing, Koepka said with a smile: "There's a little bit of an age difference there."

He added: "He's a little bit older. But I don't see it as a rivalry. I mean, it's just golf ... it's just really been the last couple [of] years.

"So I don't see it as a rivalry, although it is fun to play against him, the best player to ever play the game. You guys want to talk about rivalry, I think that's pretty cool to hear. It's exciting for me.

"But I'm just looking forward to this week, to playing with him. It'll be interesting. We haven't been paired together too much, especially over the last couple of years. He's been in the group in front or group behind. It'll definitely be interesting."