NATO Chief Jens Stoltenberg has urged the United States to stick together with Europe as the Western military alliance turned 75 on Thursday amid the Russia Ukraine war.

Stoltenberg said at a ceremony at NATO's Brussels headquarters that he does not believe in America alone, just as he claimed not to believe in Europe alone.

He stressed that he believed in America and Europe together in NATO, stressing that fundamentally, the world is stronger and safer together.

Stoltenberg said, after a Belgian military band played the NATO anthem that North America also needs Europe, stressing that through NATO, the United States has more friends and allies than any other major power.

The Kremlin's full-scale invasion of Ukraine in 2022 re-invigorated NATO as it seems to be confronted by one of the most serious challenges since it emerged from the ashes of World War II to counter the Soviet Union.

Reports have it that he alliance has bolstered its forces across eastern Europe and grown to 32 members after Finland and Sweden joined its ranks.

With the War refocused NATO's attention on its old nemesis Moscow to the east, there are also reports of another threat unnerving allies from the United States in the west.