West Ham have announced the signing of Taty Castellanos from Lazio on a four-and-a-half-year deal.

The forward is West Ham's second signing of the January transfer window after Pablo, as the club continue to boost their attacking options.

The Argentinian, who has joined in a deal reportedly worth £25.2m (€29m), will be available for the Hammers' crunch clash with Nottingham Forest on Tuesday.

Castellanos joined Lazio from New York City FC in 2023, making 98 appearances in competitions and netting 22 times for the Serie A club.

However, this season he made just 11 league appearances, scoring just twice from 2.0 expected goals (xG). He also registered three assists from just eight chances created.

"I'm really happy because it's a very important challenge for me personally, and I've come to contribute, to try to help the team as much as I can," Castellanos told the club's website.

"Every match is a battle, and I'm here to contribute that, to try to bring that energy, that fighting spirit I have inside, so that every match is as important and as tough as possible.

"I hope to give my all to the fans. I've always defended the jersey of every team with the utmost responsibility, and I want to tell them that I'm going to give everything to defend this jersey, and obviously, to achieve our goals day after day. That's the most important thing."

West Ham sit 18th in the Premier League table, four points behind Forest, ahead of this week's meeting, with the pressure building on Nuno Espirito Santo.

Following Castellanos' arrival, fellow attacker Callum Wilson, who joined on a free transfer only five months ago and has scored four Premier League goals this season, is reportedly in talks to leave the London Stadium.