The sale had been approved by the US State Department in December.

"We are strengthening the iron fist of the Polish Army... to efficiently deter the aggressor," Polish Defence Minister Mariusz Blaszczak said during a signing ceremony in Warsaw.

The defence ministry said the value of the contract was $1.4 billion (1.3 billion euros), with $200 million financed by the US side.

Blaszczak said the first tanks under the deal were set to be delivered later this year to eastern Poland.

Last year Poland bought 250 Abrams tanks from the US which, according to the Polish minister, should be delivered in late 2024.

Signing the deal on the second batch comes more than 10 months into the war in neighbouring Ukraine, which spilled over the border last month when what is thought to have been a Ukrainian surface-to-air missile landed in Poland, killing two people.