admits England will face the "biggest test" of its World Cup ambitions when its face France in a blockbuster quarterfinal on Saturday.
Southgate's side recovered from a nervous start before powering to a 3-0 win against Senegal in Sunday's clash at the Al Bayt Stadium.
England will return to the Al Khor desert at the weekend for a titanic showdown with a France team looking to become the first team to win successive World Cups since Brazil in 1958 and 1962.
While England looked impressive once Jordan Henderson
put the Three Lions ahead against Senegal, with Harry Kane
and Bukayo Saka
also netting against the African champions, Southgate knows Didier Deschamps
' team are a significant step up in class.
"It is the biggest test we could face. They are world champions, with an incredible depth of talent and outstanding players. They are very hard to play against and score goals against," Southgate said. "It's a fantastic challenge. It's a historic rivalry with great games from the past. It's a brilliant game for us to be involved in and test ourselves against the very best."
Fulled by Paris Saint Germain striker Kylian Mbappe
, France beat Poland 3-1 just hours before England joined Les Bleus in the quarterfinals. Mbappe struck twice against the Poles and already has five goals in this year's tournament.
"Mbappe is of course a world-class player. He has already delivered big moments in this tournament and in previous tournaments," Southgate said. "[Antoine] Griezmann
is also a phenomenal player, we know [Olivier] Giroud
so well and they have outstanding midfield players as well. It is a huge test but one we are really looking forward to."
England captain Harry Kane
agreed with Southgate's glowing assessment of France, saying: "Saturday will be a really tough evening. France are a great team. They are the reigning champions. If you want to win the World Cup you have to play the best sides in the world and France are definitely one of them."
Although England has good reason to fear France, Southgate can counter by pointing out his team is rounding into form as it enters the business end of the tournament.
England has already scored 12 goals in four matches at this year's World Cup, the country's joint-most at a single major tournament.
The key to England's victory against Senegal was Borussia Dortmund midfielder Jude Bellingham
. Bellingham became the first teenager to register an assist in a World Cup knockout match since 1966 when he laid on Henderson's opener.
The 19-year-old was also involved in Kane's goal and proved the catalyst for all England's best moments as it turned the tide following Senegal's bright start.
Saluting Bellingham's development just two years after he was playing in the English second tier with Birmingham, Southgate said: "I think the biggest thing is the mentality. We've done a lot of work with young players over the years but the thing that makes the difference, is the mindset, the drive, the desire to learn. He has all of that. I don't think we could predict how quickly he would mature. That's gone to another level in the last three months.
"We've wanted to invest in young players on the basis they could be something special. You suffer a bit with that at first because they are not going to be perfect when they come in. Further down the line, you get these types of performances."
Watching Kane score his first goal of the tournament was another boost for Southgate.
"You could see the lift that gave Harry. His link play started to come together again," he said. "For any striker when you haven't scored it's in the back of your mind and when you get that goal it is a great lift of confidence. That will do him the world of good." smg/rcw
© Agence France-Presse