After talks in Kyiv, the African delegation will meet Russian President Vladimir Putin to urge an end to the conflict. Meanwhile, Ukraine says its counteroffensive is advancing in the south.
African leaders were due to meet Russian President Vladimir Putin on Saturday in the northwestern Russian city of Saint Petersburg, a day after talks with their Ukrainian counterpart.
The African diplomatic team traveled to Kyiv on Friday to call for peace after their continent was hit hard by rising grain prices due to Russia's invasion of Ukraine.
The leaders include South African President Cyril Ramaphosa, Senegalese President Macky Sall, Zambian President Hakainde Hichilema and Comoros President Azali Assoumani, who also currently heads the African Union.
"There should be peace through negotiations," Ramaphosa told Ukrainian President Volodymyr Zelenskyy and quoted Nelson Mandela several times during a news conference that followed the talks.
The calls were rebuffed by Zelenskyy, however, who said that "to allow any negotiations with Russia now that the occupier is on our land is to freeze the war, to freeze pain and suffering."
The African leaders were forced to shelter when air raid sirens sounded across Kyiv due to the detection of incoming Russian missiles.
The Ukrainian Air Force later said it shot down 12 missiles, including six hypersonic ones.
While there was no reported damage inside the city, seven people including two children were wounded, the regional police said.
Kyiv: Ukrainian forces advancing in the south
Ukrainian troops are making good progress in southern sectors in their counteroffensive against Russian occupation troops, Ukrainian military officials said.
Deputy Ukrainian Defence Minister Hanna Maliar said on the Telegram messaging app that troops were "engaged in active moves to advance in several directions at once."
Brigadier General Oleksandr Tarnavskyi, commander of Ukrainian troops in the southern Tavriia sector, said there had been 36 combat engagements and 578 attacks in the past 24 hours.
"The enemy's losses in killed and wounded amounted to more than four companies," he wrote on Telegram. A company typically consists of 100–250 soldiers.
Maliar also said Russian forces were trying to dislodge Ukrainian forces from established positions in the east of the country.
Ukrainian forces around the devastated city of Bakhmut, captured by Russia last month, were trying to push Russian forces out from the outskirts of the town.
Colonel General Oleksandr Syrskyi, the head of Ukrainian ground forces, earlier described the situation in the east as tense, with Russia bringing its best divisions into the Bakhmut sector with backup from artillery and aircraft.
"Every soldier, every new step we take, every meter of Ukrainian land freed from the enemy is of utmost importance," Ukrainian President Volodymyr Zelenskky said in his nightly video message.
Russia has not officially acknowledged Ukrainian advances in the early stages of a counteroffensive and said it had inflicted heavy losses on Kyiv's forces in the previous 24 hours.
Kyiv said on Thursday it had regained control of about 100 square kilometers (38 square miles) of territory in just over a week of its counteroffensive.
UK: Moscow reinforces attack helicopter force
Russia has boosted its attack helicopter force since the start of Ukraine's counteroffensive, Britain's Defense Ministry said Saturday.
In its latest intelligence briefing, the ministry said Moscow had deployed an extra 20 military helicopters to the Berdyansk airport, some 100 kilometers (60 miles) from the frontline.
Britain said it was likely that Russia has gained a temporary advantage in southern Ukraine as its attack helicopters could launch longer-range missiles against Ukrainian ground targets.
Russia's Defense Ministry published several videos and pictures over recent days showing numerous strikes on Ukrainian-manned armored vehicles and tanks from Ka-52 attack helicopters and drones.
Moscow said its forces had destroyed several German-made Leopard tanks and US-made Bradley fighting vehicles while repelling a Ukrainian counteroffensive.