United States president Donald Trump blasted Golden State Warriors head coach Steve Kerr and San Antonio Spurs boss Gregg Popovich for their responses to questions about the NBA-China controversy.

Houston Rockets general manager Daryl Morey issued an apology on Sunday for a now-deleted tweet, that read "Fight for freedom, stand with Hong Kong" amid the ongoing protests in the region.

The issue has highlighted the NBA's relationship with China, which Kerr was noncommittal about on Monday when asked about the fallout from Morey.

Kerr and Popovich have been highly critical of Trump in the past and the country's leader was scathing of the NBA coaches.

"I watched this guy, Steve Kerr, and he was like a little boy who was so scared to be even answering the question," Trump told reporters Wednesday when asked about Kerr's refusal to discuss the issue.

"He couldn't answer the question. He was shaking. 'Oh, I don't know. I don't know.' He didn't know how to answer the question. And yet he'll talk about the United States very badly."

On Popovich – who was also reluctant to discuss the issue of protests in Hong Kong – Trump said: "I watched Popovich. Sort of the same thing, but he didn't look quite as scared actually.

"But they talk badly about the United States, but when it talks about China, they don't want to say anything bad. I thought it was pretty sad actually. It'll be very interesting."

Trump added: "I watch the way that Kerr and Popovich and some of the others were pandering to China, and yet to our own country, it's like they don't respect it.

"It's like they don't respect it. I said, 'What a difference – isn't it sad?' It's very sad. To me, it's very sad."

Made aware of Trump's comments about Kerr, Warriors superstar Stephen Curry – who has also been critical of the US president – replied: "welcome Steve to the club".