President Moreno - who came to power in 2017 - said of the decision to end Assange's seven-year stay in the embassy: "Any attempt to destabilise is a reprehensible act for Ecuador, because we are a sovereign nation and respectful of the politics of each country".
In a video announcement after Assange's arrest, Moreno accused Assange of "discourteous and aggressive behaviour" inside the embassy, and said that WikiLeaks made "hostile and threatening declarations" during Assange's time in the embassy.
The comments show the degradation of Julian Assange's relationship with Ecuador, which allowed him to stay in the London embassy for almost seven years.
Footage from Russian state broadcaster Ruptly shows Julian Assange, heavily bearded, being forcibly removed from Ecuador's London embassy on Thursday.
"We can not allow our house, the house that opened its doors, to become a centre for spying", added Moreno, who was elected in 2017.
Dubbed "Collateral Murder", the footage prompted worldwide concern over the conduct of U.S. forces stationed in the Middle East, something supporters of WikiLeaks argue remains behind Washington's renewed drive to extradite Assange to face charges in the United States.
Meanwhile, as journalists and commentators joke about his plight, Assange is languishing in the UK's notorious maximum Belmarsh Prison where he awaits a United States extradition hearing for the crime of committing real journalism.
A war of words has broken out between the Ecuadorian government and Wikileaks' founder Julian Assange.
Ecuador's attempted character assassination of whistleblower Julian Assange stepped up since his arrest last week, with officials offering various excuses to justify his expulsion - and the media has been eagerly lapping it up.
U.K. Home Secretary Sajid Javid would be expected to have the final say in which extradition claim takes priority, if Sweden does file a new one.
He made the move after losing his battle against extradition to Sweden where he faced allegations including rape.
The Ecuadorean president also said that the health of Assange, 47, ...
If Stockholm makes a formal extradition request, the British government will have to decide whether to consider it before or after that of the United States.
Assange, who appeared much older when he emerged from the embassy than when he sought refuge there in August 2012, has denied the Swedish rape allegation, asserting the sex was consensual.