LONDON (AP) — British Prime Minister Andy Burnham said Monday that the U.K. will help Ukraine make its own long-range missiles by sharing classified technical information for British components.

Burnham, who was in Kyiv alongside other international leaders for Ukraine’s Independence Day, said defense firm MBDA will release details on U.K.-made parts for the SCALP missile to Ukraine to help the country assemble the weapons.

However, experts say that won’t result in operational missiles soon — or address Ukraine’s most pressing needs in its war against Russia’s full-scale invasion.

Here’s what to know about the missiles and how significant the announcement is for Ukraine:

What the SCALP missile is

The SCALP missile is the French-produced version of the U.K.’s Storm Shadow, an air-launched, high-precision missile with a range of more than 250 kilometers (155 miles). Both use shared French and British technology.

Measuring 5.1 meters (16.7 feet,) the missile is hard to detect and is designed to hit fixed or stationary targets such as hardened bunkers and key infrastructure, according to MBDA. The defense firm says the missile uses an advanced navigation system and is exceptionally accurate.

Storm Shadow and SCALP missiles are in service with the British, French and Italian air forces, as well as other export countries. They have been used in conflicts in Iraq, Libya and Syria.

The missiles won’t be ready till next year at the earliest

Ukraine is already in talks with France, which recently agreed to help set up assembly lines for the missiles in Ukraine so that Kyiv can produce its own version of the weapons. It is not known how far advanced the plans are, or when such missiles may become operational.

“Any impact … will in part depend on how quickly Ukrainian-assembled SCALP cruise missiles can be introduced into service,” said Douglas Barrie, a senior fellow at the International Institute for Strategic Studies.

Arun Dawson, a researcher at the Freeman Air and Space Institute at King’s College London, said the news won’t help Ukraine through this winter and likely won’t start having an effect until next year, at the earliest.

“What Ukraine needs is protection from Russian ballistic missile attacks,” he said.

Ukrainian President Volodymyr Zelenskyy said on Sunday that his country is receiving substantially fewer Patriot defense systems, even as Russian ballistic attacks are increasing. The shortfall is particularly serious because the United States and European partners are struggling to expand production.

What a SCALP missile can do, Dawson said, is equip Ukraine with deep strike offensive ability. “You can use it to take out the Russian sites from which they are launching these ballistic missiles,” he said.

Matthew Savill, director of military sciences at London’s Royal United Services Institute, noted that Ukrainian development of its own ballistic and cruise missiles will complement the mass of firepower it can launch using drones, which are relatively slow and not that stealthy.

A weapon like a SCALP missile “has a sophisticated warhead and strikes the target at a velocity that means it can penetrate hardened structures and destroy buried targets in a way a slower drone without such a warhead is unable to do, at present,” Savill said.

The British announcement on Monday drew ire from Russia. Kremlin spokesman Dmitry Peskov accused the U.K. of “fanning the flame” of the war on Kyiv’s side — a claim Burnham swiftly dismissed.

“Who started the fire?” Burnham asked reporters Monday.

The UK has supplied Ukraine with missiles since 2023

Britain became the first country to supply longer-range strike weapons to Ukraine in 2023 when it donated a number of Storm Shadow missiles to Kyiv. The missiles gave Ukraine capacity to strike targets in Russia well behind the front lines, as well as in Russian-occupied Crimea.

The U.K. is also helping Ukraine develop low-cost strike weapons in other ways.

Officials have been working with British defense companies to test a new ground-launched strike system that could hit targets more than 500 kilometers (310 miles) away while carrying a powerful 225-kilogram (496-pound) warhead.

Sylvia Hui, The Associated Press