President Donald Trump made a cutting jab against the Scottish independence movement during his trip to Scotland, saying the United Kingdom should only allow independence referenda every 50 or 75 years because a country “can’t go through that too much.”

The remark enraged Brian Cox, a Hollywood actor born in Dundee and supportive of Scottish independence, who made his feelings against “that idiot in America” known in a new interview with Sky News.

“He’s talking b——s. I’m sorry, but he does. It’s rubbish. Let’s get on with it and let’s get it done. We can do it,” said Cox. “It’s been tough as there’s a great deal of undermining that has gone on.”

He added that the long-running fraud probe into the pro-independence Scottish National Party has been a big impediment to the cause.

Scotland, which has been part of the United Kingdom since 1707 and has gradually pushed for greater autonomy and self-governance in the face of dissatisfaction at English power over their policy, hosted an independence referendum in 2014 that only narrowly lost.

Supporters of the movement point to the painful history of English suppression of their culture and the fact that an independent Scotland would have full control over its national affairs, with critics noting that Scotland stands to be much poorer as an independent country. The push for a second referendum was fueled in part by Brexit, as Scotland voted to remain part of the European Union, while the United Kingdom as a whole voted to leave.

Trump has a number of financial interests in Scotland, most notably his golf properties, and it has been a frequent source of tension for locals. The president recently melted down after a Scottish newspaper accurately identified him as a “convicted felon.”