The deal, signed on Wednesday last week, is likely to result in an US military presence in the country, according to a report from Telesur.
It now seems unlikely that Ecuador President Lenin Moreno will pay heed to calls to restore Assange's Internet access.
Last month, Assange lost his Internet access after Ecuador took what it said was a step to stop him from interfering in other countries' affairs and pulled the plug.
But WikiLeaks said Ecuador had asked for removal of a tweet that said: "In 1940 the elected president of Catalonia, Lluís Companys, was captured by the Gestapo, at the request of Spain, delivered to them and executed. Today, German police have arrested the elected president of Catalonia, Carles Puigdemont, at the request of Spain, to be extradited."
It added: "This is the only tweet the government of Ecuador asked to be removed. In an email to his London lawyers on 27 March at 14:54 BST the Ecuadorian foreign ministry referenced no other matter."
Moreno's cosying up to the US contrasts with his predecessor, Rafael Correa, who had refused to take part in a US-sponsored plan for the country.
Assange has been taking refuge in the Ecuadorian embassy since June 2012. He was recently granted Ecuadorian citizenship and given diplomatic status in the hope that the UK would allow him to leave the embassy.