Adam Peaty says breaking the 57-second barrier in the 100m breaststoke is "very, very possible" and his main motivation going into the World Aquatics Championships.

World and Olympic champion Peaty defends his title in the event on Sunday in Gwangju, South Korea.

The 24-year-old set a world record of 57.10 at last year's European Championships in Glasgow and admits smashing that time is constantly on his mind.

"I think it's the first thing I think of when I'm in the pool and the last thing I think of when I'm out of it, just because that is my main motivation now," said Peaty.

"How do I get below that magic 57? How do I get below my world record?

"I know it's very, very possible. But I need to be in the right frame of mind, I need to have the right body, everything has to go almost perfect."

Peaty is also the reigning world champion in the 50m breastroke and will compete in that event on Tuesday.

The Englishman set the world record of 25.95 in the 50m at the 2017 worlds in Budapest, but could not match it in Glasgow last year, recording a time of 26.09.

Having firmly established himself as the man to beat over both distances, Peaty is keen to enjoy competing as he deals with the pressure of expectation, with the 2020 Olympics in Tokyo on the horizon.

"I think when you go into a World Champs it can get very tense, it can get very hostile," added Peaty, who won gold in the 100m at Rio 2016.

"But at the same time, I've got to remember why I started it and that was just because I love racing, I love winning, and I don't want to take that fun out of it.

"I don't want to get to that position where I feel like I almost defend myself. I should be attacking, and that's what I go by.

"I know what I want out of sport, I know what time I want, I know what kind of objectives to hit at World Championships or Olympics, but at the same time, it's all about longevity for me."