Ricardo Patino will meet Assange at the embassy in London on June 16, and has offered to hold talks with Foreign Secretary William Hague to try to reach an agreement over Assange's future.
The Australian has been inside the embassy since June 19 last year and has been granted political asylum.
He is wanted for questioning in Sweden over allegations by two women, which he denies. Assange fears if he travels to Sweden he will be extradited to the US for questioning over publication by WikiLeaks of confidential information.
An Ecuadorian government spokesman said: "Mr Patio will be in London and has offered to meet with Foreign Secretary William Hague."