Head coach Simon Middleton says England "improved the game" in their professional demolition of the United States, but called on other nations to back their women's sides.

Since giving full-time contracts to 28 players in 2019 England have dominated the game and are world number ones.

"We haven't just improved our game, we've improved the women's game," Middleton said on BBC Two.

England's four wins mean they remain top of the world rankings after earlier claiming back-to-back record wins against five-time world champions New Zealand.

Canada perhaps provided the most challenge, but fell to a 51-12 defeat, and the latest win is England's biggest since beating Scotland in the 2011 Six Nations.

"We've shown what's possible when you back the girls and you're given the resources and you put them in the right environment," Middleton added.

'The best spectacles are really competitive'

Middleton wants other unions to follow in England's footsteps.

The Welsh Rugby Union announced its first professional contracts for women's players earlier in November, while France are semi-professional, 10 Scotland players have contracts and Ireland get a set amount of money per day when they play.

Middleton cited Saturday's "unbelievably competitive" men's matches, with both England beating South Africa and Wales defeating Australia by just one point.

The head coach suggested more of the same was needed in the women's game to grow the crowd from the 7,515 who attended at Sixways.

"The best spectacles are really competitive spectacles," he said.

"From a coaching point of view yes. we would like all the plaudits to be on us, but that's not what makes a game a spectacle for the spectators.

"There is an emphasis on the nations around us to take their game forward. The other nations can get behind their national women's team and keep pushing them on.

"We are trying to be as good as we can be. If you get that level of product every week, you will get the competition you saw in the men's games on Saturday."

'We won't stop until we're perfect' - Aldcroft

Despite such a dominant autumn, England believe there is work to do before next year's World Cup.

Middleton expects New Zealand and Canada to come back stronger, while France - who hope to stop England winning three Six Nations titles in a row in April - looked dangerous in back-to-back victories against the Black Ferns.

Zoe Aldcroft, England captain for the first time in Worcester, agreed as she added: "We're not going to stop until we're perfect.

"We're never going to get perfect in a game of rugby. We're never going to stop working towards that."

But Middleton took time to praise the "first-class attitude" of his players, adding there is a growing understanding of "what it takes to be a professional player at the very highest level".

England's autumn - the stats

'Rowland is like Wilkinson with more pace'

England have shown impressive strength in depth this autumn, with Aldcroft and Abby Dow the only two players to have started all four Tests and several players making their debut.

Questions over how they would survive without star centre Emily Scarratt - who broke her leg in September - have been erased by such huge scorelines.

Middleton also believes concerns over who can fill retired World Cup-winning fly-half Katy Daley-Mclean's boots have been allayed by Helena Rowland and Zoe Harrison's impressive performances in the 10 shirt.

"Helena Rowland is like Jonny Wilkinson," he said.

"He had an unbelievable all-round game and she's got that. She's like Jonny Wilkinson but with a bit more pace.

"At the same time I take my hat off to Zoe Harrison. We have seen her come out of her shell both as a player and a leader.

"She is unrecognisable from the player who walked into the door at the start of the autumns. In Zoe and in Helena we have got two great players, which is what we needed after Katy left. We're in a good place."