The striker he has not given up hope of staying on Teesside, but he is aware there is no better shop window to parade his talents than South Africa 2010.

Killen was one of New Zealand's stars in yesterday's 1-1 Group F draw against Slovakia as the All Whites earned their first World Cup point in dramatic fashion, 21-year-old defender Winston Reid heading home the equaliser in the third minute of stoppage time.

He said: "As of next month I'm a free agent. It's a big time for me and an opportunity for me to alert clubs. I'm good to go next month and see where it takes me.

"There's possible ongoing talks but I haven't spoken to the manager (Gordon Strachan) in a month. I'm not worried about that now. I just want to help New Zealand to get through this group."

New Zealand take on Italy on Sunday in Nelspruit, where a good performance would give them real hope of going through to the second round.

Killen said: "A goal against Italy would do me no harm. It would be something to be proud of to score against the world champions.

"We can't wait for that game. The press have written us off from day one but I think we've shown we deserve more respect.

"We're not going to get carried away. We've got the world champions in the next game and we are a minnow in football status. We'll put our heart into and see how we go."

The 28-year-old has put his honeymoon to wife Hannah on hold until after the World Cup. They were married in Loch Lomond earlier this month and had just one night's holiday before Killen's World Cup duties intervened.

New Zealand captain, Blackburn'sRyan Nelsen, also believes his side could now produce an even bigger upset.

"We need a win," said Nelsen. "If we can get a win against Italy or Paraguay you never know. We could go through. It's exciting.

"Everyone out there was looking at New Zealand and thinking we were making up the numbers. It really annoyed everybody because we are a pretty good team."

Meanwhile, Liverpool defender Martin Skrtel is worried how the disappointment of losing a goal so late will affect Slovakia psychologically in their first World Cup finals.

Skrtel said: "It was very disappointing and we are very sad because if you concede a goal in the last minute it is not good for the head. But that is football and that's life.

"In the first half we did not play well and after half-time we started playing our real game and scored a goal. Then we made one mistake and conceded a goal and it's not good."

But he urged Slovakia to snap back against Paraguay on Sunday with all four teams in Group F locked on one point each.

Skrtel added: "We have lost nothing really because all the teams in our group have one point and now we have two games against Paraguay and Italy before us and we need to keep our head up and try to win these games."

He also had a message for his Liverpool team-mates Steven Gerrard and Jamie Carragher, who take on Algeria with England on Friday.

"It was unlucky for England against the United States," said Skrtel of the 1-1 Group C opener. "I hope Stevie and Carra will play in the next game and I know they can win that game. They will go through to the next round, I'm sure."