The European Union has considered taking measures "urgently" amid deadly fighting in the eastern Democratic Republic of Congo.
After Rwandan-backed forces seized a second major city amid an escalation of their years-long fighting against DRC government forces, the EU said on Saturday it was "urgently" considering all options in response to the widening rebel offensive.
Having captured the key provincial capital of Goma last month, M23 fighters pushed south and took a vital airport before marching virtually unchecked into another key city, Bukavu, on Friday, according to local officials and humanitarian sources.
"Alarmed by news of Rwandan-backed M23 forces seizing Kavumu airport and entering Bukavu, ignoring international appeals for ceasefire," European Commission spokesman Anouar El Anouni wrote on X, formerly Twitter.
"The EU urgently considers all the means at its disposal. The ongoing violation of the DRC's territorial integrity will not go unanswered."
Meanwhile, Corneille Nangaa, leader of the Congo River Alliance [Alliance Fleuve Congo (AFC)], a political-military coalition of groups including the M23, seeks to overthrow the government of the DRC’s President Felix Tshisekedi.
Nangaa has vowed to march thousands of kilometers from the eastern region to take Congo's capital city Kinshasa.
Hundreds of armed groups are fighting in eastern DRC, aiming to gain control of mineral resources rich swathes of the country.
One of the world's biggest lithium deposits is said to be in the country. The metal has medicinal applications and is also used in a variety of rechargeable batteries for electric vehicles, mobile phones, and laptops.
Last month, the Rwanda-backed Tutsi-led M23 rebel forces have quickly moved southward after seizing the key eastern city of Goma, the main city in the mineral-rich east where Chinese firms have been making investments. The Congolese government accuses Rwanda of sowing chaos in the region in order to benefit from its rich resources, a claim Rwanda has denied.
Speaking at the Munich Security Conference, DR Congo's President Felix Tshisekedi called for Rwanda to be sanctioned, accusing it of having "expansionist ambitions", the AFP news agency reports.
"We will no longer put up with our strategic resources being plundered for the benefit of foreign interests under the complicit gaze of those who feed on chaos," he is quoted as saying.
Meanwhile, the continent's heads of state are meeting for the African Union (AU) summit in Ethiopia.
At the summit opening in the Ethiopian capital Addis Ababa on Saturday, UN chief Antonio Guterres said a regional escalation "must be avoided at all costs".
It follows an appeal from the European Parliament, which this week urged the EU to suspend a minerals deal with Rwanda.
Lawmakers in Strasbourg on Thursday overwhelmingly approved a non-binding resolution that also called for the bloc's 27 member states to freeze all direct budget support as well as military and security assistance to Rwanda.
Meantime, the rebel forces' advance continues despite the international calls for a ceasefire and a resumption of peace talks between Kinshasa and the rebels.
In recent weeks the DRC conflict has killed thousands and driven vast numbers from their homes. There are reportedly 350,000 internally displaced people in Congo, presently.