West Ham United joint-chairman David Sullivan has confirmed that the club will be making more signings during this summer's transfer window.

The Hammers have already brought in four new players since the end of the 2013-14 season, including Argentine striker Mauro Zarate and midfielder Diego Poyet from Charlton Athletic.

Sullivan told the club's website: "The players we have signed so far were all high up on our list of priorities and I know they will all add something different to our squad, exciting attacking play, goalscoring and experience as well as potential.

"The recruitment drive will carry on, though, as there are at least three more positions we would like to strengthen. We are in advanced talks to secure another one of our top targets and all being well we should get that deal over the line in the next 72 hours.

"I think come kickoff in our first game against Spurs, we should have at least three more players so I'd like to think we'll go into the new season with a real sense of optimism about we can achieve."

Chelsea winger Christian Atsu and Ecuador striker Enner Valencia are among those to have been linked with the club in recent days.