Prime Minister Rishi Sunak said he will continue using the name Brecon Beacons for the national park, even though it has dropped the English name.
The park switched to using its Welsh name Bannau Brycheiniog National Park earlier this month, as its management claimed the association with a wood-burning, carbon-emitting blazing beacon was “not a good look”.
The decision was criticised by senior Tories as a symbolic attempt to look “trendy” which could “undermine” the region’s international identity.
The Prime Minister told BBC Wales he was a “big supporter of the Welsh language and Welsh culture”.
“But when it comes to the Brecon Beacons, the first thing to say is this is an internationally renowned place to visit, attracts visitors from all around the world.
“It’s something we’re all really proud of across the UK.
“I’m going to keep calling it the Brecon Beacons, and I would imagine most people will do that too.”
Last week, Downing Street said it expected people to carry on using the Brecon Beacons name and actions “rather than nomenclature” were the key to tackling climate change.
“The public, I’m sure, will continue to … use both the English and the Welsh names,” the Prime Minister’s official spokesman said.
Welsh Secretary David TC Davies has expressed concern about the rebranding, saying there had been “no consultation” and it would “always be known by (Brecon Beacons) to so many around the world”.
Welsh Tory leader Andrew RT Davies said: “The Beacons are as recognisable outside of Wales as they are here. Why undermine that?”
The Welsh name for the region translates as “peaks of Brychan’s kingdom” – a reference to the fifth-century king in the region.