"Our economy grew 3.5 percent in the first half of 2014, and is forecast to grow 2.5-3.5 percent for the year," he said in a message on the eve of National Day.

The forecast is within previous official estimates of 2.0-4.0 percent growth this year even as the city-state grapples with increasing uncertainties around the world.

The government on July 14 said gross domestic product shrank an annualised 0.8 percent on-quarter in the three months to June due to a fall in the output for electronic goods, a main export for the country of 5.4 million people.

Lee said the tiny island republic had thrived due to globalisation but remained vulnerable to external shocks.

"Events overseas affect us quickly and unpredictably, such as political changes in Southeast Asia, maritime disputes in the South China Sea, or armed conflicts in Gaza and Ukraine," he said.

The 62-year-old premier said the government was continuing to strengthen social safety nets, especially for the country's growing ranks of elderly citizens.

The government in February announced an Sg$9.0 billion ($7.2 billion) package to provide life-long healthcare subsidies to elderly citizens.

Affluent Singapore has one of the world's most rapidly ageing populations due to falling birth rates and longer lifespans.

Officials say 20 percent of Singaporeans will be 65 or older by 2030.

"Our population is ageing, and our seniors have fewer family members to support them," Lee said.

"They need peace of mind in their silver years. They want to be assured that they can retire happily after a lifetime of hard work," he added. Singapore celebrates its 49th independence day on Saturday.