The Colombian defender believes the Rossoneri will soon be competing for Champions League glory after last claiming the prize in 2007
The Serie A giants are one the most successful clubs on the continent but they have not made it past the quarter-finals of the Champions League since winning the competition in 2006-07.
However, Zapata is hopeful they will soon be able to challenge for top honours once more.
"We want to re-establish the club as the force it once was in the Champions League," Zapata told the official Uefa website.
"That is definitely what we are working hard to achieve: to make Milan big again on an international level.
"It will be hard work, but with the lads we have we will get there."
Milan will be looking to overturn a 1-0 first-leg defeat when they take on Atletico Madrid at the Vicente Calderon on Tuesday evening as they aim to reach the last eight of the Champions League.