The United States on Monday approved a $12 billion sale of Apache attack helicopters to Poland, a giant deal with a frontline ally supporting Ukraine in its war against the Russian invasion.

Poland will receive 96 AH-64E Apache attack helicopters from their manufacturer Boeing, the State Department said in a notification to Congress of the sale's green light.

Poland decided last year to seek the Apaches to replace its aging Soviet-era helicopter fleet as concerns mounted over Russia's military action in neighboring Ukraine.

The sale "will improve Poland's capability to meet current and future threats by providing a credible force that is capable of deterring adversaries and participating in NATO operations," a State Department statement said.

Polish Defense Minister Mariusz Blaszczak confirmed the purchase on social media, adding that "until the procedures are completed and the purchased helicopters are delivered to Poland, the US Army will provide us with Apache helicopters from its own resources."

Poland has robustly supported US-led efforts to support Ukraine against the Russian onslaught, with a large portion of the billions of dollars in US weapons provided to Ukraine crossing the border through Poland.

Poland announced in January that it plans to spend four percent of its gross domestic product on defense this year -- well above the NATO target of two percent.

In June, it received the first Abrams tanks as part of a $1.4 billion deal for the combat vehicles previously used by the US Marine Corps.

Last year, Poland bought another 250 Abrams in a more modern M1A2 variant, which are expected to be delivered in late 2024. It will be the first country outside the United States with the tanks.

The Ukraine war has solidified the relationship between the United States and Poland, whose conservative government had earlier butted heads with President Joe Biden's administration on issues including LGBTQ rights and media freedom.

In the statement, the State Department called Poland "a force for political stability and economic progress in Europe."

Congress has the right to review and block the helicopter deal but objections are not expected.