Washington DC - The US said Thursday it had approved a $2.68-billion sale of bombs to Canada, where Prime Minister Mark Carney is sharply expanding defense spending amid uncertainties over relations with Washington.

The State Department said the air strike weapons will include up to 3,414 BLU-111 bombs, which weigh 500 pounds each and can hit troop formations, and up to 3,108 GBU-39 bombs, which are meant to hit stationary targets with accuracy.

It also includes more than 5,000 JDAM kits to turn unguided bombs into guided munitions.

The sale "will improve Canada's credible defense capability to deter aggression in the region, ensure interoperability with US forces, and strengthen Canada's ability to contribute to shared continental defense," the State Department said in a notification to Congress.

Canadian Prime Minister Mark Carney said in August that the country would this year meet a NATO target of spending 2% of GDP on defense, years ahead of schedule.

He pointed to growing uncertainties about the role of the US, Canada's neighbor and longtime guarantor of security under NATO, as well as the prospect of Russian aggression in the Arctic.

US President Donald Trump has repeatedly questioned the wisdom of NATO, accusing allies of relying excessively on the US while not carrying their own weight.

Trump has often belittled Canada, especially before Carney replaced Justin Trudeau as prime minister, saying that it should be the 51st state of the US.