LONDON (AFP) - England must "move on to the next level" if they are going to compete with South Africa later this season, according to Kevin Pietersen. The South Africa-born batsman, who controversially turned his back on the Proteas in order to pursue an international career with England, believes the team must start to improve this season if they are to have a chance of wresting back the Ashes next year from Australia. England won the 2005 Ashes series on home soil 2-1 but were then overwhelmed 5-0 in Australia in 2006-07. "We are going to have to (move on to the next level), if we are going to beat South Africa," Pietersen told reporters at Lord's here on Monday. "That's going to be the toughest series we have had for a long time, apart from Australia. "I know how South Africa play their cricket. I play like South Africa play their cricket - tough, in your face, will do anything to win and really knuckle down. It's going to be a hard series. "That's the series we're looking at targeting to see where we are at because it's going to be a pretty important summer, next summer." But before that four-Test series, England are up against New Zealand in a three-Test campaign, starting at Lord's on Thursday. England had to come from behind to beat the Black Caps 2-1 in New Zealand in March, with Pietersen's painstaking 129 in the final Test in Napier providing the platform for a series-clinching 121-run victory. And for all his comments about South Africa, Pietersen insisted neither he nor England were taking their eyes off the here and now. "We're not talking about South Africa yet, we are talking about New Zealand and wanting to beat them and beat them well," the 27-year-old Hampshire batsman added. New Zealand may be a side with few star names but they routinely punch above their weight and Pietersen said: "They are under-rated, they've got real quality bowlers, real quality batters, they play as a unit and their fielding is electric. "They are under-estimated and we are not going to under-estimate them. We pulled off a bit in the first Test match we played there and then we buckled down," Pietersen said. In a comment that may not endear him to the New Zealand management, Pietersen added: "Teams like Bangladesh don't have any world stars but they pull out victories every now and then. That's what cricket can do." Some pundits have suggested that if England don't beat New Zealand 3-0 they will have demonstrated a worrying lack of ruthlessness. But Pietersen, who warmed up for the first Test by scoring a century for Hampshire against Somerset, said: "I haven't won a Test match at Lord's since I started playing for England so 2-0 will be great." Pietersen, who played the first of his 36 Tests against Australia at Lord's, a match that saw England beaten, in 2005, added: "A draw is what we normally get here because it's such a flat wicket, unless it's Australia." Last year, Pietersen was rated the world's best batsman and was averaging over 50, a mark which if maintained over a long career signals a player as an outstanding batsman. But Pietersen said it was playing more innings like the one he did in Napier where he was at the crease for nearly five hours - in contrast to his attacking reputation that interested him, not statistical landmarks "I think I have learned to play the situation really, really well," said Pietersen, who has now scored over 3,000 Test runs at an average of 49.74 with 11 centuries. "That's something I've been striving for. At times you can get caught up with playing how everybody thinks you should play be playing and how you think you should be playing but what helps the team, that's the way you should be playing. That's where I've tried to get my game to." "One of my career highlights was the hundred in New Zealand. When the team needed me to stand up and be counted. I stood up to be counted. That's the stuff that really interests me. When England need me, I like to perform."