Elon Musk's X has offered to make changes to its blue checkmark for "verified" accounts, a European Commission spokesman said Friday, after the platform received a 120-million-euro ($138 million) fine.

The European Union slapped the fine in December on X for breaking its digital rules including through the "deceptive design" of its blue checkmark.

"X has submitted remedies in relation to its blue checkmark. The commission will now carefully assess the proposed remedies," EU spokesman for digital affairs Thomas Regnier said.

He did not provide details about what X had submitted.

X risked periodic financial penalties, had it not submitted any remedy.

"We have to value the fact that after a constructive exchange with the company, the company has taken its obligation seriously and has submitted us remedies," Regnier told reporters in Brussels.

When contacted by AFP, X did not provide comment immediately.

Blue checkmarks, long free of charge at what was previously known as Twitter, were intended to signal the identity of certain users -- such as celebrities, journalists and politicians -- had been verified in an effort to build trust in the platform.

But after Musk bought the platform, he allowed users to pay to get one.

X in February announced it had filed an appeal with the EU's top court against the fine, which was the first ever under the bloc's Digital Services Act (DSA).

But Regnier said the commission still expected X to pay it by Monday, and to provide further remedies on other breaches by April 28.

The fine came under a probe started in December 2023.

That investigation continues as EU regulators study how X tackles the spread of illegal content and information manipulation.

X has often been in the EU's sights.

The 27-nation bloc in January began another DSA probe into the company's AI chatbot Grok's generation of sexualised deepfake images of women and minors after a global outcry.