The Barcelona forward told a news conference in Malmo on Friday that he had missed playing for his country.
GEAR:Get a Sweden shirt
"If I'm chosen for the next game (a home friendly against Scotland on August 14), I'll be there," said a smiling Ibrahimovic who will share the captain's duties with midfielder Anders Svensson.
"A motivated Zlatan is worth his weight in gold for the Swedish national team," Hamren said.
Ibrahimovic, 28, quit internationals last year following Sweden's failure to qualify for the World Cup in South Africa.
"I am proud (to be captain), it feels fantastic and I'll do my best to be the leader that Erik wants me to be," Ibrahimovic said, adding that he had been impressed by Hamren who took over from Lars Lagerback in November.
Ibrahimovic endured a difficult season at Barcelona in which he started many games on the substitutes' bench and the signing of Spain's David Villa will increase the competition for places.
"I was a Barcelona player when I left (at the end of the season) and I'll be a Barcelona player when I return," said Ibrahimovic who has scored 22 goals for his country in around 60 internationals.
Sweden face World Cup runners-up the Netherlands, Finland, Hungary, Moldova and San Marino in their Euro 2012 qualifying group.
