Explainer: Why Cluster Bombs Used In Ukraine Are Banned By 120 Countries

Cluster bombs have been deployed in many recent conflicts, including where US forces were involved.

Controversial cluster munitions supplied by the United States are being used by Ukraine in their counteroffensive against Russia, a White House spokesman John Kirby has said. "We have gotten some initial feedback from the Ukrainians, and they're using them quite effectively," White House national security spokesman John Kirby told reporters on Thursday.

Although Moscow, which had earlier said it would use "similar" weapons if the United States supplied cluster bombs to Ukraine, is yet to react to the announcement, the claim by the White House official has triggered outrage from some allies and humanitarian groups.

What are cluster bombs?