Ukraine is in desperate need of more air defense assets, and this week's NATO summit in Washington gives President Volodymyr Zelensky an opportunity to push Kiev's supporters for additional batteries to protect against Russian strikes.
Zelensky will attend the summit, which marks the 75th anniversary of the transatlantic alliance and will bring together leaders of countries that have provided tens of billions of dollars in military aid to Kiev to help it resist the Russian invasion.
Since Ukraine is unlikely to receive an invitation to join NATO, which it is seeking, the new air defense funds are the most concrete assistance it is likely to receive at the summit.
Below, AFP examines key questions about Ukraine's air defense needs and how they might be addressed.
What systems does Ukraine want?
Zelensky has argued for months that his country does not have enough air defense systems and has asked for at least seven more Patriot batteries in addition to those already donated by the US, Germany and the Netherlands.
Over the weekend, the Ukrainian leader praised the air defense donations but said "more concrete solutions" are needed "to protect all our towns and villages and really overcome Russian terror."
"Next week we will work with our partners on such solutions - preparations are already underway," he said.
Why does Ukraine need them?
Russia is exploiting gaps in Ukraine's air defences to launch devastating strikes against civilians and infrastructure, as well as shelling Kiev's front-line troops.
On Monday, Ukrainian officials reported that more than 30 people had been killed by a wave of dozens of rockets that hit cities across the country and destroyed a children's hospital in Kiev.
Russia, meanwhile, said it had recently attacked three Ukrainian air bases, raising questions about how Kiev will protect the fleet of F-16 fighter jets due to arrive in the country later this year.
And Ukraine has pointed to a lack of air superiority as a major factor limiting its military's ability to advance on the battlefield after Kiev's inconclusive counter-offensive in 2023.
Ukraine's international backers are seeking to assemble a multi-layered air defense for the country consisting of short-, medium-, and long-range systems that can defend against a variety of threats.
But to do so from a mix of a variety of new and older Western and Soviet-era systems in the midst of active conflict has proven seriously challenging, and shortcomings remain.
What will Kiev get?
The United States is reportedly considering donating another Patriot battery to Kiev, which considers them particularly valuable because it is one of the few systems capable of shooting down the most advanced Russian missiles.
On Monday, U.S. President Joe Biden pledged action to bolster Ukraine's defenses in a statement in which he described Moscow's missile strikes that day as "a horrifying reminder of Russia's brutality."
"Together with our allies, we will announce new measures to strengthen Ukraine's air defenses to help protect its cities and civilians from Russian strikes," Biden said in the statement, without giving specifics.
Washington is also in talks to potentially transfer up to eight Patriot batteries from Israel to Ukraine, US media reported.
The Netherlands, for its part, is leading efforts to build a Peitrit missile system from various components from various countries' stockpiles.
Germany and Romania have already responded to Zelensky's pleas for the Peitrit by pledging one additional system each, and Italy has said it will donate an advanced SAMP/T air defense system. I BGNES