A married couple were killed and 11 people were hurt in the area outside Kyiv, the regional administration said. A dozen residential buildings and at least 60 cars were also damaged.
Ukraine has been warning for weeks that Russia could be stockpiling missiles to launch a major air attack on the energy system, now power outages across Ukraine.
The attack began hitting different districts of Kyiv in the early hours of Saturday, with more waves coming as the sun came up.
Russia fired 43 cruise missiles at targets overnight. Ukrainian air defenses shot down 36 of them.
Ahead of Rosh Hashanah Israelis take trains from Poland to reach Uman in Ukraine.
Kyiv Mayor Vitali Klitschko said that one person was injured in the historic Podil neighborhood and a fire broke out near one of the city's parks.
Musk said he had no choice but to reject an emergency request from Ukraine "to activate Starlink all the way to Sevastopol."
Iohannis was speaking a day after Kyiv said Russian drones had detonated on Romanian territory, a claim Bucharest denied.
The US government has so far provided more than $43 billion in weaponry and other military aid to Ukraine.
Reuters' witnesses heard several blasts which sounded like air defense systems being deployed at around 05:50 a.m.