The proposed digital market bill aims to curb the power of American technology giants.

Apple boss Tim Cook took aim at the proposed EU rules aimed at curbing the power of US technology giants on Wednesday, saying they may pose a security and privacy risk to the iPhone.

In his first public comment on the Digital Market Act (DMA) proposed by EU antitrust chief Margrethe Vestager, Cook stated that some are good, but others are not. He said he was worried that the draft rules would cause more app installations not from Apple’s App Store, or “side loading.”

“You give an example here, I don’t think it’s in the best interest [of the user]: The current DMA language under discussion will force sideloading on the iPhone,” Apple’s CEO said when speaking remotely at VivaTech, the largest technology conference in France.

“So this will be the ultimate way to install apps on the iPhone,” he said. “It will undermine the security of the iPhone, as well as the many privacy initiatives or privacy intrusion tags and app tracking transparency we have built into the App Store.”

Earlier this month, EU legislator Andreas Schwab, who led the European Parliament’s review of draft rules, said he hopes to strengthen legislation and narrow it down to big companies such as Google, Amazon, Apple and Facebook.

Cook said that Apple will participate in the debate and try to find a way forward.