The 29-year-old enjoyed six successful seasons with Celtic before becoming a free agent at the end of the last campaign.
While teams such as Everton and Sevilla have reportedly shown an interest in Samaras, the forward claims that he will only consider his options once Greece leave Brazil.
"Celtic made me feel important, they made me feel like I am one of the best players in the team and it made me play better at all levels," he is quoted as saying by Sky Sports News.
"I am only thinking about the national team and nothing else for now. At the moment I am thrilled because I have given joy to my countrymen."
Greece return to action on Sunday when they face Costa Rica in the second round of the World Cup.