A bun fight is underway between Saskatchewan Premier Brad Wall and the A&W hamburger chain.

A&W Canada advertises that there's no added hormones or steroids in its beef, which it gets from Canada but also from foreign countries, including the U.S., New Zealand and Australia.

That fact has rankled some Canadian ranchers.

And a new TV commercial promoting the chain's "Better Beef for a Better Burger" campaign apparently attracted the attention of Wall on the weekend.

"There is another ad from @AWCanada promoting non-Canadian beef," Wall said on his Twitter account. "Guess we can support Cdn beef restaurants like @McDonalds."

Brad Wall

Premier Brad Wall has weighed in on hambuger chains that use non-Canadian beef. (Adam Hunter/CBC)

The tweet drew a response from Susan Senecal, the president of A&W Food Services of Canada.

"It's interesting to see," she told CBC News. "Saskatchewan was one of the very first provinces where we were able to source our beef."

The chain known for its family of burgers buys "millions of pounds" of beef from Saskatchewan annually, she said.

"A lot of our ranchers are in Saskatchewan," Senecal said, adding in the past year "thousands of head of cattle" from Saskatchewan have been added to A&W's supply chain.

While it's not at 100 per cent, the percentage of Canadian beef A&W uses continues to grow, she said.

Senecal didn't say what percentage of Canadian beef is in its hamburgers, however.