Jeremy Clarkson sent David Cameron a "genuinely worried" text message from Argentina after filming a Top Gear episode that sparked a diplomatic row.
The Prime Minister revealed Clarkson sent the message as the former Top Gear crew were forced to flee the country while filming a Christmas special.
The team, including co-hosts James May and Richard Hammond, were given diplomatic assistance by the Foreign Office after trouble erupted when it emerged they were using a Porsche with the registration number H982 FKL, which some suggested could refer to the Falklands conflict of 1982.
Mr Cameron was speaking as he toured the offices of a television production company in Chiswick, west London, owned by the trio.
He said: "My children, they watched the Patagonia episode five times."
Clarkson replied: "That's not the one to watch - that one did not go well," before Mr Cameron added: "That's why they liked it. They liked the idea that I was going to step in and rescue you."
May said: "We quite liked the idea of that you would step in as well."
Mr Cameron continued: "You did actually send me a genuinely worried text."
Clarkson confirmed: "I did," and appeared to suggest he had done so because he feared they would be unable to get back to the UK.
Former Top Gear executive producer Andy Wilman subsequently denied the number plate was a "stunt", while the BBC rejected a demand from Alicia Castro, Argentina's ambassador to the UK, for a public apology.
Clarkson, 56, is a friend of the Prime Minister through the social network known as the Chipping Norton Set, and lives in his Witney constituency in Oxfordshire.
He added that work on the trio's new Amazon Prime motoring show The Grand Tour, which will make its debut on the streaming service in the autumn, is "going really well".
When asked to comment on the revamped Top Gear, now fronted by Chris Evans and Matt LeBlanc, he said: "We are just working on our programme."