The Gunners are set to complete the move for the £105 million midfielder after weeks of negotiation with the Hammers
Declan Rice will complete his British record move to Arsenal on Saturday after the club informed West Ham that all outstanding paperwork will be completed in the next 24 hours.
The West Ham captain had previously agreed a deal with Mikel Arteta's side at the end of June, but the clubs are yet to confirm the agreement as they hash out the structure and legalities of the transfer.
The England star's £105 million move is set to make him the most expensive English player in Premier League history.
Ahead of the deal, Rice has been in Portugal, training alongside Manchester United's Bruno Fernandes, and his Portugal team-mate Rafael Leao of AC Milan at luxury sports complex The Campus, in Quinto do Lago in the Algarve region.
British media reported on Tuesday that the weeks of delay were set to end imminently as the Hammers sent through their final approved wording on the deal to Arsenal's lawyers.
With the final sign-off from the Gunners' camp the announcement will call time on months of discussions as Arsenal nab their No 1 long-term transfer target.
A number of involved parties alluded to being in the dark about the timing of the deal, including the 24-year-old's manager, David Moyes.
On media duties for the Hammers as they start their pre-season tour in Australia, the Europa Conference League-winning manager claimed he received most of his updates on the deal's progression from Sky Sports.
“I've just been listening to Sky, and I've been taking the news from Sky,” Moyes quipped. “I know nothing about it. You (journalists) seem to know more about it than me, and getting the news quicker than me. So, I'm happy to listen to what you people say.
“Until it's done, we can't plan anything. We'll wait and see what happens. Everybody knows the situation, we're expecting something to happen. I think you just said it was done two weeks ago and it's still not done.”
West Ham previously shared an enormous hint about the player's future with the launch of their new Umbro kit - the related imagery not containing any photographs of the future club legend.