SINGAPORE, Aug. 9 -- Singapore Prime Minister Lawrence Wong has urged Singaporeans to hold fast to the spirit of unity that built the nation six decades ago, warning that the years ahead will bring sterner tests amid a more fractured and volatile world.

Delivering his National Day message yesterday from the Padang - the historic field where Singapore's first National Day Parade was held in 1966 - Wong said national cohesion, resolve and performance would be crucial to staying ahead in an era of deepening geopolitical tensions and economic uncertainty.

"As a small nation, we cannot afford to be divided. Our unity has always been our source of strength. When we stand together, there is nothing we cannot overcome," he said, recalling how t...