The government said the Wikileaks founder's social media messages "put at risk" their relations with other countries
Ecuador has cut off the internet access of Julian Assange, who remains in their embassy in London.
The Wikileaks founder has been holed up in the Ecuadorian embassy for more than five years, but has frequently used social media to communicate with the outside world.
His internet access has been briefly suspended in 2016, after Wikileaks published hacked emails from members of Hillary Clinton's presidential campaign.
Earlier this week, he published a series of tweets questioning the decision of more than 20 countries to expel Russian diplomats in solidarity with the UK's claims Moscow was responsible for the Salisbury spy poisoning.
Assange wrote: "The manner of and timing of Russian diplomatic expulsions is poor diplomacy. The expulsions occurred 12 hours after one of the worst building fires in post Soviet history, which killed at least 64. Russians will see the timing as gratuitous.
"That 21 US allies have expelled diplomats over an unresolved event in the UK and that the US expelled nearly three times as many diplomats as the UK, the alleged victim country, helps the Kremlin further a narrative that it is under conspiratorial siege led by the US."
(3/3) Further, while it is reasonable for Theresa May to view the Russian state as the leading suspect, so far the evidence is circumstantial & the OCPW has not yet made any independent confirmation, permitting the Kremlin push the view domestically that Russia is persecuted.— Julian Assange ? (@JulianAssange) March 26, 2018
In a statement today, the Ecuadorian government did not refer to any particular incident, but claimed Mr Assange had breached a commitment to not 'interfere with the affairs of other states'.
The government claims his social media messages "put at risk the good relations that [Ecuador] maintains with the United Kingdom, the rest of the European Union member states, and other nations."
Mr Assange was granted political asylum by Ecuador in 2012.
He had been wanted by Swedish officials for questioning over a rape allegation, and Mr Assange feared he would be extradited to the United States if he was arrested by Swedish officials.
Sweden has since dropped their investigation, but the Wikileaks founder still faces arrest if he leaves the Ecuadorian Embassy in London.
Last month, a judge in the UK ruled the arrest warrant against him remains valid because he skipped bail in June 2012.
Mr Assange - whose organisation has published confidential documents relating to the US intelligence services - is the subject of a "very serious criminal investigation" in the US, officials have previously admitted.
It remains unclear if a formal US extradition warrant against Mr Assange exists.
Earlier this year, it was confirmed he had been granted Ecuadorean citizenship.