Manuel Pellegrini has targeted "four or five" signings to launch a blueprint of attacking football at West Ham.
The former Manchester City manager has signed a three-year deal as West Ham boss, succeeding David Moyes.
Now the 64-year-old will get to work on dragging West Ham back up the table following this season's 13th-place finish.
"West Ham have a very good team. I know all of the players and I saw most of the games last season," said Pellegrini. "So I am sure, with the players we have in this moment, and bringing maybe another four or five in, we are going to have a strong team.
"I am excited about this project. I know this league is good and it's not easy, but working together we can think about reaching important targets for the season. I always play attacking football and we must try to reach important targets."
Pellegrini left Chinese Super League club Hebei China Fortune.
Joint chairman David Sullivan said in a statement: "I am delighted to welcome Manuel to West Ham, he is one of the world's most respected football coaches and we look forward to working with him."