Three members of a bipartisan United States congressional delegation called on Prime Minister Lee Hsien Loong yesterday evening at the Istana, where the two sides affirmed the longstanding and multifaceted relationship between the two countries.

The lawmakers belong to the Congressional Singapore Caucus, established in the US House of Representatives in 2002.

The caucus co-chairs - Representative Bradley Byrne, a Republican, and Representative Denny Heck, a Democrat - and Democratic congressman Rick Larsen are part of a caucus of almost 50 members that serves as a platform to build ties between the two nations.

At yesterday's meeting, Mr Lee and the congressmen exchanged views on regional and international geopolitical developments, and underscored the importance of American engagement in Asia.

The delegation also called on Deputy Prime Minister and Coordinating Minister for Economic and Social Policies Tharman Shanmugaratnam yesterday.

During their five-day visit, the delegation will meet other Cabinet ministers and tour Changi Airport.