The US plans to send cluster munitions to Ukraine, a decision that supports Ukraine’s ammunition needs despite concerns from allies and human rights groups over the use of widely banned weapons.

The latest U.S. military aid package for Ukraine, announced on Friday, includes dual-purpose advanced conventional munitions, or 155mm artillery shells containing cluster munitions.

Cluster munitions consist of small bombs scattered over a wide area to maximize enemy casualties. Ukraine and Russia already use cluster munitions.

Human rights groups have opposed the US sending cluster bombs. Cluster munitions can accidentally kill civilians on the first detonation, or by detonating unexploded submunitions weeks, months, or years after they hit the ground.

The White House has been refusing to send the ordinance for months, despite Ukrainian requests. On Friday, National Security Advisor Jake Sullivan said the weapons failure rate would be below 2.5 percent. It’s unclear how the White House arrived at this test result, amid concerns that the actual failure rate may be higher.

Last week, Colorado Democratic Rep. Jason Crow asked the Pentagon for information on UXO rates, ammunition types, and fuses that can affect UXO rates.

Crow said Friday that the decision to send munitions “draws a stark contrast between two conflicting interests. It is not only the humanitarian danger posed by these munitions, but also the existential and survival implications. It is the need to support Ukraine in the war at stake,” he said.

Ukraine has long requested the supply of ammunition as a way of alleviating pressure on the use of conventional artillery ammunition, which is consumed at a rate of thousands per day.

Laura Cooper, Assistant Secretary for Russia, Ukraine and Eurasia, testified that the Pentagon was also aware of the usefulness of using weapons. One Pentagon assessment released as part of the Discord leak said cluster munitions would be effective against the type of human-wave attack that Russia employs.

But the US hesitated for months to comply with Ukraine’s request. Cluster bombs are banned in most countries, including many of Washington’s allies in Europe.

Lawmakers also said pressure from allied nations was hampering the delivery of cluster munitions, with one senior parliamentary aide pointing specifically to opposition from France and Germany.

At the same time, the White House faced increasing pressure from Congress to send cluster munitions to Ukraine.

In March, Republican leaders on the Senate and Senate Armed Services Committees, the House Foreign Relations Committee, and the Senate Foreign Relations Committee wrote an open letter to pressure the Biden administration to send cluster bombs.

Many Democrats also supported the decision, with Senators Mark Kelly (D-Arizona), Senator Joe Manchin (D-), and Senator Tammy Duckworth (D-) issuing a joint statement supporting the decision. Announced.

Ukrainians who participated in the effort to acquire cluster bombs were especially grateful for parliamentary support.

The head of the Horos faction in the Ukrainian parliament, Oleksandra Ustinova, wrote on her Facebook page on Friday: Thank you to everyone on my side,” he wrote on his Facebook page.