RIO DE JANEIRO • A gold medal in the inaugural Olympic rugby sevens tournament would surpass the achievement of winning the World Cup twice with the all-conquering All Blacks, New Zealand's Sonny Bill Williams said on Wednesday.

The highest-profile player at the tournament, former heavyweight boxing champion and rugby league international Williams was part of the New Zealand teams that won the 2011 and 2015 World Cups.

"It would have to surpass it, I think," he told a news conference in Rio on Wednesday.

"As an athlete there is no higher level than the Olympics. I am fortunate to learn off these boys in the team and train my butt off. We want to be successful."

The 31-year-old is one of the few top players from the 15-man game to have managed the transition to the lung-busting shorter format.

"It has been a tough old year but now it is the big stage, the big one," he said.

"The key was putting myself in the sevens environment in the whole year and learning from these boys. The fitness levels are up where they should be and the knowledge is too."

New Zealand have been pooled with Japan, Kenya and Britain in the first round of the men's tournament, which begins next Tuesday.

Williams' emphasis on the Olympics comes as a contrast to golf's return to the Games, where many top men golfers have not travelled to Rio, citing Zika fears or placing little importance on winning a medal.

World No. 4 Rory McIlroy, one of the absentees, previously said he may not even "watch the golf tournament at Rio on the television".

"Different people have different opinions. But I'm very happy with the decision that I've made and I have no regrets about it," he said.

"I'll probably watch the Olympics, but I'm not sure golf will be one of the events I watch."

When pressed which events he would watch, he replied: "Probably the events like track and field, swimming, diving… the stuff that matters."

REUTERS