PARIS - Singapore has to manage the complex issue of foreign workers and immigration carefully, Prime Minister Lee Hsien Loong told a gathering of French businessmen on Tuesday.

It has to be done in a way which is "sustainable over the long term for our society, politically, and also achieves the demographic and economic objectives that we have", he added at a business forum here for French entrepreneurs keen to explore opportunities in Singapore and Asia.

Singapore society must be able to handle the number of foreigners, and new immigrants must be integrated and not be so overwhelming that they dilute the country's core, values and ethos, Mr Lee said.

He noted that foreigners are needed to meet Singapore's economic and demographic needs.

"You need that range of skills and experiences and talent which no society can generate on its own, and you have to get them from all over the world - Europe, America, China, India," he said.

He also made the point that Singapore must do things in an open way so that it maintains its links with other countries, and develop "win-win mutually beneficial relationships".

Mr Lee, who arrived in Paris on Sunday, was speaking at a France-Singapore Business Forum hosted by Medef International, the French Business Confederation.