In the Sahel, terrorist groups regularly attack local and international security forces. The violence is spreading to coastal states along the Gulf of Guinea, the chief was quoted as saying.
In Nigeria, Boko Haram and its splinter factions are terrorising local communities and attacking security forces, despite the efforts of the Multinational Joint Task Force.
"We are seeing terrorist networks across Libya and North Africa, stretching through the Sahel to the Lake Chad region, and present in the Democratic Republic of the Congo and Mozambique," Guterres said.
He added, "This is a battle we are not winning. And this is not just a regional issue, but a clear and present danger to global peace and security."
The UN chief also warned that the impact of the crisis in Libya is growing and spreading throughout the region, as weapons and fighters continually move across borders.
Peace in Mali is also essential, he said, expressing hope that despite the terrible attacks in the Mopti region last week, plans for an inclusive political dialogue will facilitate the implementation of the 2015 peace agreement.
Guterres asked for support for African military operations, including the African Union's peacekeeping mission in Somalia, the joint military force of five Sahel countries, and the multinational task force against Boko Haram.
He said climate crisis is another vital preventive measure as climate-related risks, including droughts, floods and changing rainfall patterns, often intersect with political, social and economic factors.
"We must urgently reduce emissions to prevent catastrophic consequences for sustainable development and security across Africa, and step up support for the countries most affected," Guterres stressed.
Nearly half of Africa's population of 1.3 billion are under the age of 15. Education, training and job opportunities for this generation must be central to any development strategy. Women's meaningful participation and leadership are essential to last peace, the UN chief said.
He stressed the importance of sustainable and inclusive development, which, he said, is the most effective way to address the underlying causes of conflict, extremism, and terrorism.
Tackling poverty and inequality, strengthening state institutions and civil society and promoting human rights are essential to preventing conflict, and building resilient communities and societies, the chief said.
When prevention fails, the UN works with partners to reduce suffering, resolve conflicts and build sustainable peace, he said.
The UN strongly supports the African Union's 'Silence the Guns 2020' initiative as a basis for advancing peace and security and offering a safer and better future, he said.
The largest UN peacekeeping missions are on the African continent, where more than 80,000 peacekeepers serve. Africa is now the largest troop-contributing region to UN peacekeeping operations, said Guterres.
"We owe these Blue Helmets our strong and united support, through robust funding and strong mandates," he added.
Across the continent, the UN is working in steadfast and close cooperation with the African Union and African sub-regional organizations to prevent and resolve conflicts, he said.