Tshisekedi is participating via video link, according to his office. Others participating in the meeting in Dar es Salaam are the presidents of Kenya, Somalia, Uganda, Zambia, and Zimbabwe.
The Rwanda-backed militia M23 and Rwandan troops captured Goma in eastern Congo-Kinshasa last week and are now moving into the neighboring province of South Kivu.
The militia's advance has led to the deaths of thousands of people and many have been driven from their homes.
The UN Human Rights Council condemned Rwanda's support for rebel militias in eastern Congo-Kinshasa on Friday and will also establish an expert group to investigate human rights abuses.
