VOLGOGRAD, June 22 (Xinhua) -- Nigeria coach Gernot Rohr admitted his side had improved after the break as Ahmed Musa scored two goals to give his side a 2-0 win against Iceland in Volgograd on Friday.

The win leaves Nigeria in second place in Group D, knowing at a draw in their last game against an Argentina side in crisis will almost certainly see them into the last 16.

"It is a final in the group," admitted Rohr, looking ahead to the game against Argentina.

"We recently played them (Argentina) in a friendly in Krasnodar and we beat them 4-2 although there was no Messi," commented the Nigeria boss.

Rohr highlighted that Nigeria were an inexperienced side and would have to avoid errors in their penalty area.

"We have had two games and conceded two penalties, and both were committed by young players. This World Cup comes a bit early for us and we will be better in 2022, but we have a good chance of beating Argentina," he commented, adding that the key on Friday was "to make good counter-attacks, we are a bit faster than Iceland and maybe we have the technical ability to play one or two touches."

Icelandic boss, Heimir Hallgrimsson admitted his side were below their best and put that down to a combination of temperatures of over 30 degrees centigrade in the Volgograd Arena and the effectiveness of Nigeria.

"It wasn't a great game and we have played better, but I thought we all did our best, it could have been the high temperatures, but Nigeria played very well and they were hard to face today," he said.

"The first half was more or less as we wanted, it was 0-0 at the break, but the goal at the start of the second half, changed things: we had to push forward and Nigeria are very quick on the break.

"They were organized and first to the second ball and we have to give them credit," said Hallgrimsson.

"My players gave everything and all we have to do now is beat Croatia (to qualify). We've played them four times in four years and we're like a married couple that wants a divorce," he said with a smile.