The Sunderland striker is back in the squad for the qualifiers against Wales and Belgium after ending an 18-month impasse between himself and the manager.
Fletcher had not spoken to Levein since sending a text message to a Scottish Football Association official in February 2011 informing him he did not wish to be selected for the Carling Nations Cup game against Northern Ireland.
But he has enjoyed positive talks with Levein in the past week and is eager to get back involved.
In an interview on www.scottishfa.co.uk, Fletcher said: "I had a good chat with the manager when he came to visit at the training ground last week and, while it was important we discussed the past and put it to bed, it was more important that we focused on the future.
"I understand why people want to know what changed, but the truth, as the manager said last week, was that the situation wasn't helping anyone. I am a proud Scot and it is a privilege to play for my country.
"Everyone knows it has been too long since we last qualified for a major finals and I want to do my bit to help us reach Brazil."
Levein also expressed his regret last week that the situation had taken so long to resolve.
Fletcher said: "I am desperate to play for Scotland again and, like Craig, I regret that it has taken this long to come about. I'm sure we have both done a lot of thinking during the last two years, but the country comes first.
"I think it just became apparent that we all needed to move on. The most important thing is that I can look to restart my international career.
"When I first spoke to Craig again it was fine and was not awkward at all. We both said our piece and agreed that whatever happened, the country comes first."