KINSHASA -- Tensions remained high in the Democratic Republic of the Congo (DRC) on Tuesday as the March 23 Movement (M23) rebellion advanced in the country's North Kivu and South Kivu provinces.

President of the DRC Felix Tshisekedi is expected to address the nation amid the humanitarian crisis and major advances by the rebellion in the eastern part of the country, a DRC official said late Monday. However, he did not specify the exact time of the president's national address.

Vital Kamerhe, president of the National Assembly, the country's lower house of parliament, made the announcement after a high-level meeting chaired by Tshisekedi on the humanitarian and security situation in Goma, the capital of the North Kivu province, which is currently facing attacks by the rebels.

Since Sunday evening, gunfire has been heard across Goma, a city with over 700,000 internally displaced people living on its outskirts. On Monday morning, fighting intensified in various parts of the city, including areas near the border with Rwanda, local sources told Xinhua.

"Active combat zones have spread to all neighborhoods of the city," Bruno Lemarquis, the deputy UN envoy and top UN humanitarian official in the DRC, told a news conference on Monday. The situation in Goma remains "fast-evolving," he added.

Other local sources said the rebels gained the upper hand after capturing Mount Goma, a strategic hill 1,500 meters above sea level in the city's center. Several M23 columns entered neighborhoods in the city, and residents saw their movement along both major and minor roads.

According to UN sources, the border between Rwanda and the DRC near Goma was closed Monday morning. For several days, a significant number of Goma residents crossed the border to seek refuge in Gisenyi, a Rwandan town bordering the DRC, where panic has been mounting amid reports of gunfire.

In its latest statement released early Monday, M23 announced that the "liberation of the city has been completed" and that "the situation is under control" following a 48-hour ultimatum given to Congolese soldiers.

According to sources in the UN peacekeeping mission, the rebel group has taken over several important facilities, including the airport, the port, and a DRC military base. The latest report from a UN group of experts said the rebels have also seized several towns and established a parallel administration.

A second emergency meeting of the UN Security Council is expected to be held on Tuesday over the security situation in eastern DRC.

UN Secretary-General Antonio Guterres said on Sunday that he was deeply concerned by the escalating violence in eastern DRC and reiterated his strongest condemnation of the M23 armed group's ongoing offensive and advances towards Goma.

Guterres called on the M23 to immediately cease all hostile actions and withdraw from occupied areas. More than 400,000 people have been displaced since the start of 2025 in the eastern DRC, according to the UN.