The Giants were hoping the 25-year-old Tonga international, who has signed a three-year contract, would arrive in time to play in next week's friendly at St Helens.
But the former New Zealand Warriors forward has experienced a snag with his visa, meaning his work permit has yet to be processed.
"Everything was going superbly with Ukuma pre-Christmas and we expected him into the UK any day now," said Huddersfield managing director Richard Thewlis.
"Every issue from our and the RFL's perspective was sorted weeks ago but a technicality has been raised by the border agency in Manila, meaning Ukuma is now behind schedule.
"He has done all that has been asked of him by the authorities and, without going into precise detail, he has been extremely unfortunate in one area of his submission for entry which requires further work.
"I remain confident - as does Ukuma and his manager - that the issue will be overcome. It does mean, though, that he is a definite non-starter for the first trial game at St Helens a week on Friday."
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