MYKOLAIV, Ukraine — A localized ceasefire between Ukraine and Russia took effect early Tuesday ahead of a humanitarian mission brokered by U.S. first lady Melania Trump, as missile attacks resumed in Kyiv.

The local pause in fighting started at 3 a.m. to allow an aid mission into the Russian-occupied town of Oleshky in southern Ukraine later this week.

According to her office, Melania Trump led talks with civilian negotiators from Russia and Ukraine after meeting with U.N. officials who briefed her on the situation in the town.

The aid mission is planned ahead of a new round of U.S.-brokered talks between Russia and Ukraine expected next month aimed at ending the war after more than 4½ years of fighting.

Up to 2,000 people are stranded in Oleshky with dwindling food and medicine. They are unable to leave because of explosive mines and drone attacks in the area, according to the U.N.

Russian and Ukrainian negotiators as well as the militaries of the two countries confirmed in separate statements that the ceasefire had begun.

The local ceasefire is due to last through Saturday, or longer, though deep mistrust between Russia and Ukraine has thwarted previous attempts at ceasefires.

Minutes after 3 a.m., multiple ballistic missile explosions shook Kyiv and air alerts sounded in multiple parts of the country.

Late Monday, the capital also came under attack, when Russian ballistic missiles damaged the grounds of a university in Kyiv, killing one person and leaving 10 injured, city officials said. In Kharkiv, Ukraine's second-largest city, authorities said attacks late Monday killed two people and injured four.

"It is important that the world sees that Russia is showing nothing but a desire to kill and continue waging war," Ukrainian President Volodymyr Zelenskyy wrote in an online post shortly afterward.

Oleshky is in the partially occupied Kherson region, about 550 kilometers (340 miles) southeast of Kyiv, where the Dnipro River separates Russian and Ukrainian forces.

It was captured by Moscow's forces on the first day of their full-scale invasion of Ukraine in 2022. Further calamity struck in June 2023 when floodwaters inundated the town due to a dam collapse.

Oleshky sits across the Dnipro River from the city of Kherson, the region's administrative capital. Russian forces seized Kherson in the early stages of the 2022 invasion but retreated across the river several months later.

Negotiators involved in the aid mission said doctors, medicines, food supplies and water would be taken to Oleshky before evacuation corridors are opened.