Both were England Under-20 internationals, with White going a step further by playing for the full side, albeit in a non-cap match against Barbarians at Twickenham in 2019.
The London Irish scrum-half is eligible to switch because of a Scottish grandfather, while Christie, the Saracens back-row, played previously for Scotland at youth level via a Scottish grandmother.
The pair follow the likes of Cam Redpath, Gary Graham, Josh Bayliss and Sam Skinner who all plumped for Scotland having been previously been involved in the England set-up.
Townsend makes no apology for his border raids and points to the vast discrepancy in playing numbers between the two nations as he assembles a squad capable of challenging at the top end of the Six Nations Championship.
Scotland open their campaign against England at Murrayfield on February 5 where they will try to repeat their success of last season at Twickenham. Redpath was fast-tracked into the side that day and was outstanding as Scotland won 11-6.
Son of former Scotland captain Bryan, Redpath junior had been named in Eddie Jones’ full England squad for a tour to South Africa in 2018 only to pull out through injury.
The French-born, English-raised centre was persuaded to throw in his lot with Scotland, with captain Stuart Hogg understood to have had a significant say.
Townsend believes members of his squad can play a key role as “ambassadors”.
“If there is a player we feel can help us I think it's important that these connections happen over a long time,” said the Scotland coach. “We try to connect with them, give them feedback on the games, get to know them as people and show them that we are interested.
“Then, when it comes to selection, it's about following that up to say they are getting closer to the squad. The responses we've had from Ben White and Andy Christie, who have not been involved with us before, is that they are absolutely delighted to be involved.
“I think we have some really good ambassadors as players. They can talk about our environment and how they've enjoyed it, how playing international rugby for Scotland is one of the best things you can do in your life.
“Sam Skinner talked about his first cap as being the best day of his life. Others who have been in the environment and maybe not played have gone away knowing they want to come back and do all they can to make the 23.
“That's a positive. Maybe also it is rugby that suits them, suits their strengths. We look at that from our point of view, but players will be looking at that too.
“They think maybe they will get the opportunity to play the rugby that suits them that they want to play. All of it is in the mix but ultimately it is their decision and we are just delighted that we have these players.”