New Zealand are travelling to the UAE with a somewhat second-string squad, which is without regulars Finn Allen, Devon Conway, Matt Henry, Adam Milne, Daryl Mitchell, Glenn Phillips and Ish Sodhi.
Those players, however, will return to the squad when New Zealand move to England for a four-match T20I series (August 30 to September 5) that immediately follows the UAE tour. Foxcroft, Ashok and five other players - Chad Bowes, Dane Cleaver, Cole McConchie, Henry Shipley and Will Young - will also travel to England, where they won't be part of the T20I squad but will be in contention for the two warm-up T20 games against Worcestershire and Gloucestershire.
Kane Williamson (knee) and Michael Bracewell (achilles), who are recovering from injuries, were not available for selection.
Ashok is a 20-year-old legspinner who was part of New Zealand's squad at the Under-19 World Cup. He made his first-class debut in the 2022-23 season and made a significant impact, picking up 19 wickets for Auckland in the Plunket Shield at an average of 27.84.
Both Foxcroft and Ashok were part of the New Zealand A squad that played two first-class matches against Australia A in Lincoln in April.
"It's always exciting to introduce new players to the BlackCaps environment and especially so when they're on the younger side, as Adi and Dean are," New Zealand coach Gary Stead said. "Dean's been a really consistent performer domestically and that was acknowledged by the awards he picked up in March. He's a talented and adaptable batter who also bowls useful offspin - so will add to our spinning stocks which is always valued in white-ball cricket.
"Adi's only in his second year of professional cricket, but we've been impressed with his consistency and attitude with the Aces and when he's joined New Zealand A and the winter camps. With Ish Sodhi not on the UAE tour it's an opportunity to develop our next legspinner."
Stead was also pleased with Jamieson's return.
"Kyle's worked really hard and made great progress to be available for this tour and we're delighted to see him return after such a challenging year," he said. "We're all aware of his world class skills and I know he's really excited to get back with the group."