Ecuador has cut off WikiLeaks founder Julian Assange's Internet access at its embassy in London, where he has been cooped up since 2012, saying he broke a promise not to offer opinions about other countries' affairs, officials said Wednesday.

"Ecuador's government has suspended the systems that allow Julian Assange to communicate with the outside world from Ecuador's embassy in London," the National Communications Secretariat said in a statement, adding that Assange's Web access was cut off on Tuesday.

President Lenin Moreno's administration said the move was due to Assange's non-compliance with a December 2017 written pledge not to make social media posts that constitute interference in other nations' affairs.

Assange had irked Ecuador last year with his expressions of support for an independence drive in the northeastern Spanish region of Catalonia.

This month, he started weighing in on political matters once again when he took to Twitter to criticize the United Kingdom's decision to expel 23 Russian diplomats over Moscow's alleged involvement in the poisoning of former double agent Sergei Skripal and his daughter, both of whom remain in critical condition.

"While it is reasonable for Theresa May (the United Kingdom's prime minister) to view the Russian state as the leading suspect, so far the evidence is circumstantial," Assange tweeted on Monday about the poisoning, which occurred early this month in the southern English city of Salisbury.

Ecuador's government said in response that Assange's messages on social media jeopardized the South American country's "good relations with the United Kingdom, with the rest of the European Union countries and other nations."

The WikiLeaks founder has been stuck at Quito's embassy in London for nearly six years because the UK refuses to allow him safe passage to board a plane for Ecuador, which granted him political asylum in August 2012.

The Australian citizen sought refuge at the Ecuadorian mission in June 2012 after losing a long battle in the British courts to avoid extradition to Sweden, where prosecutors had been seeking to question him about rape and sexual molestation allegations dating back to 2010.

Though Sweden dropped the rape investigation last year, Assange remains unable to leave the embassy without being arrested by UK authorities for allegedly breaching his bail conditions in 2012.

Assange, who has denied all of the accusations, has said he will remain at the Ecuadorian embassy due to fears the UK will hand him over to the United States for prosecution based on WikiLeaks' publication of classified documents.