The munitions were meant for the Ukrainian military but "fell into Russian hands," one source says, warning that Iran's Revolutionary Guards can now study Western technology and reverse-engineer it.
Iran's foreign minister insists the transfer came before Russia's war on Ukraine.
The nuclear fears trigger painful memories from those who lived through the Chernobyl disaster, when Soviet authorities initially kept the accident secret.
Kyiv's support for the United Nations General Assembly resolution calling for a nuclear-free Middle East led to an angry response from Israelis online. "We always vote the same way because our position is consistently against nuclear weapons in the world," Ukrainian envoy says.
Loud explosions heard across the Ukrainian capital in the early morning as residents prepared to go to work. Some of them receive text messages from the emergency services about the threat of a missile attack.
"Once again Iran proves that it cannot be trusted and that in any area where there is killing, suffering, and hatred – Iran is there," says Herzog who is in Washington to meet the US president and other officials.
The Ukrainian president suggests that cooperation between Moscow and Tehran would not have happened had Jerusalem agreed to supply Kyiv with military aid.
Despite garnering the necessary support, former Prime Minister Boris Johnson decides not to vie for leadership, saying "I have sadly come to the conclusion that this would simply not be the right thing to do."
The Prime Minister's Office says he reiterated Israel's support for Ukraine and expressed his "deep concern" about the military connection between Iran and Russia.
The development removes one of several obstacles to Israeli support for Ukraine, The New York Times reports quoting senior officials.