United States Secretary of State Mike Pompeo and China's Foreign Minister Wang Yi separately called on Prime Minister Lee Hsien Loong at the Istana yesterday.
Mr Pompeo, who assumed the post in April, is making his introductory visit in conjunction with Asean-led meetings this week.
The Ministry of Foreign Affairs (MFA) said: "PM Lee welcomed the US' continued engagement of Asean and the Asia-Pacific region. Secretary Pompeo expressed the US' strong support for Singapore's chairmanship of Asean, and exchanged views on regional and global developments with PM Lee."
Mr Pompeo meets Foreign Minister Vivian Balakrishnan today. They will sign a memorandum of understanding to renew the Singapore-US Third Country Training Programme, which provides technical assistance and capacity building to Asean member states and Timor-Leste.
MFA said PM Lee and Mr Wang "discussed ways to further deepen and broaden the relationship, including in new areas like cooperation under the Belt and Road Initiative, the China-Singapore (Chongqing) Demonstration Initiative on Strategic Connectivity-Southern Transport Corridor, and third country cooperation".
They also discussed key issues "including the strengthening of Asean-China relationship, expediting the negotiation for the Regional Comprehensive Economic Partnership agreement, and the importance of maintaining stable Sino-US relations", the ministry added.
European Union High Representative for Foreign Affairs and Security Policy Federica Mogherini also met PM Lee, who welcomed the EU's efforts to step up ties with Singapore and Asean.
MFA said: "Both sides looked forward to the signing of the EU-Singapore Free Trade Agreement on the sidelines of the 12th AsiaEurope Meeting Summit in October, and its early ratification."
Iranian Foreign Minister Javad Zarif also met President Halimah Yacob and PM Lee this week, and both sides reviewed Iran's ties with Asean and Singapore. Mr Zarif also briefed the Singapore leaders on the Joint Comprehensive Plan of Action, and PM Lee urged Iran to continue cooperation with the international community, said MFA.