"The proposed sale will improve Poland's capability to meet current and future threats by providing air-to-air defense to protect Polish and allied forces in transition or combat and significantly improve the Polish contribution to NATO requirements," the US Defense Security Cooperation Agency (DSCA) said in a statement.

The sale "will support the foreign policy goals and national security of the United States by improving the security of a NATO ally that is a force for political and economic stability in Europe," it added.

The State Department approved the possible sale and the DSCA on Tuesday provided the required notification to the US Congress, which still needs to sign off on the transaction.

Poland has said it aims to earmark around five percent of its economic output for military expenditure next year -- a key demand of US President Donald Trump's administration for NATO members.

Most military aid to Kyiv passes through European Union member state Poland, a staunch supporter of Ukraine.