"The proposed sale will improve Poland's military goals of updating capability while further enhancing interoperability with the United States and other allies," the Defense Security Cooperation Agency said in a statement.

"Poland intends to use these defense articles and services to modernize its armed forces and expand its capability to strengthen its homeland defense and deter regional threats," it added.

Himars launchers have played a key role in Ukraine's fight against Moscow's invasion, allowing Kyiv's forces to carry out precision strikes on supply dumps and other Russian positions.

The announcement on the sale of the rocket launchers to Poland -- which shares a long border with Ukraine -- comes nearly a year after the start of Russia's invasion.

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

The M142 Himars system (High Mobility Artillery Rocket System) is a modernized, lighter and more agile wheel-mounted version of the track-mounted M270 MLRS developed in the 1970s for US and allied forces.

Himars carry one preloaded pod of six 227 mm guided rockets, or one large pod loaded with an ATACMS tactical missile.

Ukraine has repeatedly sought ATACMS from the United States, which has declined to provide them, but the sale to Poland includes 45 of them.

Poland announced a sharp increase in defense spending in late January to four percent of gross domestic product, with the prime minister saying the country needed to arm itself "faster" in light of Russia's war in Ukraine.

Warsaw had spent the equivalent of 2.4 percent of its GDP for the military in 2022, the third highest percentage among NATO countries, according to figures from the transatlantic alliance.

Other European nations have also announced increases in the budgets for their armies since Russia invaded Ukraine in February last year.

Poland, which is also a member of the European Union, has signed a series of arm deals to boost its defense capabilities in recent months.