The former Udinese man moved to the Stadio Olimpico last week along with Marco Parolo - most recently with Parma - after a six-year spell at the Stadio Friuli.
A versatile right-sided player, Basta is one of the first signings of the Stefano Pioli era as the new head coach will be tasked with improving on Lazio's ninth-placed finish last term.
Serbia international Basta is eager to help the club improve and return to Europe after missing out on qualification last season.
"Udinese was an important adventure, now a new cycle begins," he said.
"I am convinced that I have made the right choice. [My] expectations? To take Lazio back into Europe.
"Last year there were two points missing, but when you miss your target there are a lot of factors.
"It's useless to talk, we need to show it out on the pitch. My first impressions are good, I have joined a great team.
"I always want to play and I need to show I should be starting."
