West Ham have announced the signing of 19-year-old winger Armstrong Oko-Flex after his deal with Celtic expired.
Dublin-born forward Oko-Flex, who moved to Celtic from Arsenal in September 2018, joins the Irons on a two-year contract, with the option of a 12-month extension.
The Republic of Ireland Under-19s international made two senior appearances for Celtic last season, and had a brief trial spell at the West Ham academy towards the end of the campaign.
Oko-Flex, who can also play in a more central attacking role, will initially join up with the West Ham under-23s squad.
"I'm very excited to get started here. There are a lot of positives around West Ham and it's just a great club to be at right now," Oko-Flex told West Ham TV.
"I know a lot of the boys here already. I trained with some of them when I was younger, and I've played against some of them as well, so it's been good settling in and the coaches have welcomed me in very nicely as well."
West Ham academy manager Ricky Martin said: "Armstrong is someone that we've been tracking and monitoring for several months now.
"We knew that he would be available in the summer and we were absolutely delighted to invite him in for a couple of weeks at the end of last season. He came in, trained with the U23s, did really well and impressed the coaches and players.
"He's someone that we're really excited to sign. We hope he will have a very successful career with the club."
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