European Union chief Ursula von der Leyen said Wednesday that an EU-developed age verification app was ready to go, as the bloc pushes to better protect children from online harm.

The app should be rolled out in the coming months and aims to replace pop-up banners asking users to click to confirm they are over 18 to access adult content sites, EU officials explained.

"This app will allow users to prove their age when accessing online platforms. Just like shops ask for proof of age for people buying alcoholic beverages," von der Leyen told journalists in Brussels.

Brussels has been under pressure to come up with more stringent measures to safeguard children online as several EU capitals move ahead with plans to ban social media under a certain age.

To that end, a small group of EU countries including France and Italy last year started testing the age-check app that von der Leyen said Wednesday was now "technically ready".

The app uses the same model adopted during the Covid pandemic, when Brussels developed a tool allowing people to prove they had been vaccinated as countries reopened after lockdowns, she said.

Once it becomes available, users would be able to download it from an online store, set it up with their passport or ID card and then use it to prove they are a certain age.

EU digital rules require sites including porn, gambling and alcohol sellers to put in place "effective age assurance methods" to ensure only adults visit their pages.

But the European Commission, the bloc's digital enforcer, has argued the tools deployed so far are not good enough.

In March, it accused four porn sites of breaching the bloc's rules by allowing minors to access with a simple click confirming they are over 18.

"As platforms don't have proper age verification tools in place, we came up with the solution ourselves," said EU's digital chief Henna Virkkunen.

EU officials said the EU app will serve as a benchmark to test compliance and the effectiveness of alternative methods.

"Online platforms can easily rely on our age verification app. So there are no more excuses," von der Leyen said.

"Europe offers a free and easy to use solution that can shield our children from harmful and illegal content".

The app is "completely anonymous" to ensure people cannot be tracked when accessing websites, and based on open-source code, allowing non-EU states to adopt it if they wish.

Alternatives would have to respect similar privacy standards, Brussels said.

"We don't want platforms to scan our passport or face," Virkkunen said.

The app should be first adopted by seven EU countries that have been piloting it by the end of the year.

Once the system is in place, people connecting to an adult website from Europe could in practice be requested to verify their identity via that or a similar alternative.

An EU official speaking on condition of anonymity conceded the verification process might come across as "annoying" but said the harm to online surfing experience was worth it if it helped protect children.

Concerns that children and young teens could get around the checks using a VPN or asking an "older sister" for help, were well founded but missed the point, the official added.

The aim was to protect "kids" from "unintended exposure to inappropriate content" the official said, not "policing the people."

Pressure to act at EU level has been rising since Australia's groundbreaking social media ban for under-16s.

France has been spearheading the push alongside partners including Denmark, Greece and Spain, with a hotly debated ban for under-15s working its way through the French parliament.

Simeon de Brouwer of digital rights group EDRi said he doubted the app would be "practical", arguing that making platforms suitable for children was better than limiting access to them.

"The focus on age-gates itself takes attention away from the real issue: the platforms' lack of accountability for the harm they design and profit from," he told AFP. "If we address the root causes of harm, all this fuss for 'the most suitable and privacy-friendly exclusion tool' is moot."

The 27-country EU has some of the world's strictest rules regulating the digital space, with multiple probes ongoing into the impact on children of platforms including Instagram and TikTok.

Von der Leyen has advocated going further with an EU-wide minimum age limit, but first wants to hear from experts that are expected to deliver recommendations by summer.

"It is our duty to protect our children in the online world, just as we do in the offline world, and to do that effectively, we need a harmonised European approach," she said.