It is not known how long the former computer hacker will stay in the confines of the embassy, and speculation mounted that he would appear outside the building today to make a statement.
The situation will be discussed by foreign ministers from across the Americas next Friday.
The Organisation of American States (OAS) voted to hold a meeting following Ecuador's granting of asylum which Mr Assange welcomed as a ''historic victory''.
However, Foreign Secretary William Hague made it clear that the Australian would not be allowed safe passage out of the country.
Mr Assange denies the allegations he faces in Sweden and fears being transferred to America if he travels to contest them.
He enraged the US government in 2010 when his WikiLeaks website published tranches of secret US diplomatic cables.
Bradley Manning, a US army intelligence analyst suspected of leaking the information, is being held at an American military base.
He has been charged with transferring classified data and delivering national defence information to an unauthorised source and faces up to 52 years in jail.
OAS secretary general Jose Miguel Insulza said Friday's meeting would be about ''the problem posed by the threat or warning made to Ecuador by the possibility of an intervention into its embassy in London''.
He added: ''What is being proposed is that the foreign ministers of our organisation address this subject and not the subject of asylum nor whether it should be granted to Mr Julian Assange.
''That will be discussed between Great Britain and Ecuador, the issue that concerns us is the inviolability of diplomatic missions of all members of this organisation, something that is of interest to all of us.''
Tags: World News Assange Ecuador
Edited By Cen Fox Post Team
