Vermaelen, who signed a contract extension in 2011, has struck up a fine understanding with Koscielny since returning from injury last October.
"I heard the news that Laurent extended his contract and I'm really happy," Vermaelen told a press conference in Beijing on Wednesday.
"From the start when he came to Arsenal he has shown he is a great player and he is developing really well. I think he has done everything for the Club already and I hope he will stay a few more years.
"Of course he is not here at the moment because he is not fit - he had a holiday because he played in the Euros. But he is a great player and I'm happy that he signed for the Club."