The nine-page memo published Monday by the Ecuadorean website Codigo Vidrio says Assange is prohibited from "interfering in the internal affairs of other states".
It was reported on Sunday that Ecuador moved to restore Assange's access to the Internet, cell phone communications and permitted him to receive visitors other than his legal team.
In a statement, WikiLeaks wrote: Ecuador has told WikiLeaks publisher Julian Assange that it will remove the isolation regime imposed on him following meetings between two senior United Nations officials and Ecuador's President Lenin Moreno Friday.
WikiLeaks recently announced that one of Assange's longtime associates, Kristin Hrafnsson, had taken over from him as WikiLeaks editor in chief.
'The UN has already declared Mr Assange a victim of arbitrary detention.
Assange took refuge at Ecuadorean Embassy to avoid extradition to Sweden, where he faced sex crimes allegations.
The Wikileaks founder, who has been holed up at the embassy since 2012, was stopped from using the internet or a mobile phone to communicate with the outside world in March.
Friends and supporters of Assange say he has had contact only with lawyers since Ecuador suspended his communications with the outside world. During his visit to Ecuador, Kaye praised Moreno for promoting the freedom of speech and for his protection of whistleblowers. However, friends and supporters say Assange fears arrested and eventual extradition to the United States for publishing a cache of US diplomatic and military secrets on the WikiLeaks website.
President Moreno ordered Mr Assange's "isolation" on March 28 in retaliation for giving "opinions on the politics of friendly nations like Spain or the United States". High level representations were made by the Trump administration and the Spanish government over Mr Assange, who was given political refugee status by Ecuador in 2012 over USA attempts to prosecute him. "Ecuador's President until past year, Rafael Correa, has denounced Mr Assange's treatment as "torture" stating 'the government is basically attacking Julian's mental health".
Moreno later confirmed that Ecuador discussed the terms under which Assange could leave the embassy with the British government, but stressed that any such agreement must include a guarantee that London would not hand over the whistleblower to the US.