WASHINGTON, D.C.: The U.S. State Department has approved the sale of 500 Patriot PAC-3 missiles to Ukraine for an estimated $2.1 billion, clearing critical supplies that Kyiv had been waiting nearly a month to receive.

Ukraine will pay for the defensive interceptor missiles using contributions from Canada, Germany and Norway routed through the U.S. JUMPSTART program, along with national funds financed by the European Union's Ukraine Support Loan, the State Department said October 30.

The approval comes after delayed missile deliveries added to tensions between Ukraine and the United States following President Donald Trump's announcement of a diesel deal with Russia and his criticism of Ukrainian President Volodymyr Zelenskiy over Ukraine's unwillingness to halt attacks on Russian refineries.

Zelenskiy said earlier this week that Ukraine had been waiting for almost a month for the United States to sign off on critical missile supplies as Russia stepped up attacks on energy and civilian infrastructure.

The Ukrainian leader has repeatedly urged the United States to accelerate deliveries ahead of winter. The U.S. supplies missiles purchased by NATO allies under a program known as PURL.

Lockheed Martin is the principal contractor for the $2.1 billion sale.

The United States has supplied large quantities of weapons to allies while also using munitions in its own military operations in Iran, raising concerns about inventories of key air-defense and precision-guided weapons.

In July, the U.S. Army awarded Lockheed Martin a contract worth up to $58.6 billion to produce Patriot interceptor missiles.

Lockheed has said that contract would allow it to follow through on a pledge to triple PAC-3 MSE production capacity by the end of 2030.

The company also plans to increase employment at its Camden, Arkansas, plant by 50%, raising the workforce to about 1,850 from 1,200.

Lockheed previously announced that production of Patriot PAC-3 missile interceptors would increase to 2,000 units annually.

Pentagon negotiators are pressing defense contractors to accelerate production further, with tentative production agreements reached earlier this year forming part of efforts to increase missile output.