United States' Townley Haas, left, Michael Phelps, back to camera, Ryan Lochte and Conor Dwyer, right, celebrate winning the gold medal in the men's 4x200-meter freestyle final during the swimming competitions at the 2016 Summer Olympics, Aug 9, 2016, in Rio de Janeiro, Brazil. [Photo/IC]

RIO DE JANEIRO - Michael Phelps secured his third gold medal of the Rio Olympics on Tuesday as the USA won the 4x200m freestyle relay final.

Phelps joined Conor Dwyer, Ryan Lochte and Townley Haas to hit the wall in 7 minutes 0.66 seconds at the Olympic Aquatics Stadium.

Britain's Stephen Milne, Duncan Scott, Dan Wallace and James Guy took silver, 2.47sec behind the USA, and Japan's Kosuke Hagino, Naito Ehara, Yuki Kobori and Takeshi Matsuda pocketed bronze, 2.84sec further back.

Phelps, who the 200m butterfly final less than an hour earlier, swum the final leg of the race to loud cheers from the packed arena. It was the American's 21st Olympic gold medal.

Phelps has reduced his competition schedule in Rio as he focuses on butterfly and medley events.

He is aiming to become only the third athlete to win gold in the same event at four consecutive Olympics, joining Al Oerter (discuss) and Carl Lewis (long jump).

Phelps could perform the feat in both the 100m butterfly and 200m individual medley.