Some NATO member nations have expressed opposition to the use or provision of cluster munitions after the United States' recent decision to furnish them to Ukraine for its counteroffensive against Russian forces.

Cluster munitions disperse smaller bomblets, and the bomblets' high failure rates to explode, or "dud rates," pose a prolonged risk to civilians.

The Convention on Cluster Munitions, which bans production, stockpiling, use and transfer of the weapons, has been joined by more than 120 states.

Among 31 NATO members, eight nations, including the United States and Turkey have not ratified the treaty. Neither Russia, nor Ukraine are signatories to the treaty.

Spain's defense minister Margarita Robles said Madrid respects the decision of a sovereign country, but disagrees with the US decision to send cluster bombs to Ukraine.

The Canadian government told the country's public broadcaster CBC that it does not support the use of cluster munitions and it is "committed to ending the effects of these weapons on civilians, especially children."

British Prime Minister Rishi Sunak stressed that his country is signatory to the convention and that the UK has instead provided Ukraine with heavy battle tanks and long-range weapons.