Eddie Jones has signalled a ceasefire in his feud with World Rugby after praising its success in raising the standards of tier-two nations competing at the World Cup.

England have launched their group campaign with comfortable bonus-point wins over Tonga and the United States, the two lesser teams in a pool that also contains Argentina and France.

But while both victories were secured with minimal fuss, they were notable for the stubborn resistance offered by the underdogs, continuing a theme evident so far at Japan 2019.

For the first time in nine instalments of the World Cup, no team scored 50 points in a match in the opening week, ending the blight of landslide wins against smaller nations that have scarred previous tournaments.

Jones has been critical of World Rugby during the summer, describing it as 'Big Brother' on one occasion, but he has been impressed by the work put into closing the gap.

"You're seeing the tier-two countries much better physically prepared," England's head coach said.

"We've played against Tonga and America now and both of them had big, physical packs.

"They're fitter than they ever have been and that's a great thing for the World Cup, because we've got these tier-two countries fighting hard and it's producing some great rugby.

"It's a credit to World Rugby. They don't get too many credits, but they should get credit for driving tier-two development. It's great for the game."

A complaint often levelled at the sport's powerhouses is that they do not play their less established rivals frequently enough.

"World rugby is like having a little brother – they always want more. There's always only so much you can do, but just look at how competitive they've been at the World Cup," Jones said.

"They've had better preparation and there's more organisation put into their structure.

"Their players are better prepared physically and there are young players coming through. It's not perfect, but it's certainly moving in the right direction."

England's players have been given the weekend off to spend time with family before heading to Tokyo on Sunday to begin preparations for the clash with Argentina.

"We'll review the game against the USA and look at the 23 we need to play against Argentina," Jones said.

"We'll consider the conditions because Tokyo will be 27 degrees and 80 per cent humidity.

"It's going to be a wet-weather game, so we'll pick a side to play wet-weather rugby. The sun might be shining but it will be wet weather.

"This World Cup is unique because of the conditions – it's never been played in these conditions before."