The US State Department on Friday approved the sale of 500 Patriot PAC-3 interceptor missiles to Ukraine for an estimated $2.1 billion. The deal marks one of the most significant steps to supply defensive weapons to Kyiv since the beginning of President Donald Trump's second administration.

Delayed missile deliveries have strained relations between Ukraine and the US. Tensions increased after Trump announced a diesel deal with Russia and criticised Ukrainian President Volodymyr Zelenskiy over Ukraine's continued attacks on Russian oil refineries.

Ukraine has repeatedly called for more missile interceptors to counter the growing number of Russian missile attacks. The Patriot system remains one of the most effective weapons against fast-moving ballistic missiles.

On Thursday, a Russian drone strike killed at least 14 people at a crowded railway platform in Dnipro. Five others died in daytime strikes on two provincial cities, while a late-evening missile attack killed one person in Kyiv, officials said.

Zelenskiy said on Monday that Ukraine had been waiting for nearly a month for Washington to approve critical missile supplies. Meanwhile, Russia has intensified attacks on Ukrainian energy and civilian infrastructure.

However, Ukraine may have to wait several years to receive the interceptors. Weapons sales usually take years to fulfil. Two people briefed on the US decision said the missiles are yet to be manufactured and may not arrive until a couple of years into the 2030s.

Ukraine's Defence Ministry is urging the Pentagon to speed up deliveries. One possible option involves supplying Kyiv with missiles already available in the US arsenal and replacing them later with newly manufactured Patriot interceptors.

The State Department said Canada, Germany and Norway would contribute towards the purchase through the US JUMPSTART programme. The remaining funding will come from national funds financed by the European Union's Ukraine Support Loan.

The programme uses contributions from allied countries to purchase weapons, services and training for Ukraine following Russia's invasion. In August, JUMPSTART funded the purchase of 3,350 air-launched cruise missiles worth $825 million from Zone 5 Technologies and CoAspire.

Lockheed Martin will serve as the principal contractor for the Patriot missile deal.

Meanwhile, growing demand for weapons has raised concerns about US military inventories. Washington has supplied large quantities of weapons to its allies while also using munitions in its military operations in Iran.

In July, the US Army awarded Lockheed Martin a contract worth up to $58.6 billion to manufacture Patriot interceptor missiles. The company said the deal would help it fulfil its commitment to triple PAC-3 MSE production capacity by the end of 2030. It also plans to increase employment at its Camden, Arkansas, facility by 50%, taking the workforce from 1,200 to around 1,850.

Lockheed had previously announced plans to increase annual Patriot PAC-3 missile production to 2,000 units. Pentagon negotiators are also pushing defence contractors to accelerate manufacturing, with preliminary production agreements reached earlier this year.