Sadc facilitator president Jacob Zuma of South Africa is expected to brief the Troika meeting that began in Tanzania yesterday on progress made in Zimbabwe.
He will update the Troika, at its two-day meeting on political developments in Zimbabwe after which the Sadc chair President Armando Guebuza will brief the full summit.
In a statement posted on his website, President Zuma said: "The issues to be considered by the Troika, the Double Troika and the full Summit include the crisis in the eastern part of the DRC.
The Extra-Ordinary Summit is also expected to discuss the situations in Madagascar and Zimbabwe.
"South Africa will be expected to report on the facilitation process in the Republic of Zimbabwe, while the chair of Sadc will report to the Summit on the mediation process in Madagascar."
South Africa's International Relations and Co-operation Minister Maite Nkoana-Mashabane accompanied President Zuma to the summit.
President Zuma has been facilitating dialogue between Zimbabwe's coalition parties over a roadmap that should lead to harmonised elections scheduled for March next year.
Zanu-PF and the MDC formations are trying to reach a deal over the country's new constitution, which is one of the benchmarks agreed by parties in the inclusive Government before the next elections.
The parties recently agreed to form a leaner committee that should deal with contested issues in the Copac second all-stakeholders conference report.
The committee comprises Justice and Legal Affairs Minister Patrick Chinamasa (Zanu-PF), Finance Minister Tendai Biti (MDC-T) and Regional Integration and International Co-operation Minister Priscilla Misihairabwi-Mushonga (MDC).
Constitutional and Parliamentary Affairs Minister Eric Matinenga, who also sits in the committee as chairperson, said they needed a week to unlock the deadlock.
The committee is expected to submit its recommendations to GPA principals who will have the final say on the constitution-making process.