"I told (Serbia) coach (Sinisa) Mihajlovic that I will not be available for the remaining matches in 2013 because I want to step up individual work at my club with the objective of improving my performances," Subotic, the Borussia Dortmund player, said on Saturday.
"Having spoken to my club coach, Juergen Klopp, I asked Mihajlovic for his support and understanding. I'd be delighted to return next year and be part of the Serbia team aiming to qualify for Euro 2016," Subotic added in a statement released by the Serbian FA.
Serbia visit Wales on Tuesday and are at home to Balkan neighbours Macedonia on Oct. 15, but have no chance of reaching the 2014 finals in Brazil as they trail second-placed Croatia in Group A by nine points.
Subotic, 24, was out of favour in the early stages of Serbia's qualifying campaign but worked his way into the starting line-up and played the full 90 minutes against Croatia.
Mihajlovic, who has come under fire from Serbian fans and media and is undecided about whether to apply for an extention of his contract, which runs out in December, said he was surprised with Subotic's decision.
"There was no conflict between us and I don't know what the problem is, although he did say that he wants to focus on his club career," the 44-year-old coach told reporters at Serbia's Stara Pazova training base.
"There were no indications this might happen. The next qualifying campaign is another story and we will see what the future brings."
Subotic has won back-to-back Bundesliga titles with Borussia in 2011 and 2012 and lost the Champions League final to German rivals Bayern Munich in May this year.
He has scored two goals in 36 internationals and was part of Serbia's 2010 World Cup team, which made a group-stage exit.