Thats true for any country and when their ships maintenance in Singapore whats their sailors are doing in Singapore..they are doing Rest & Relaxation aka R & R and according to Wikipedia 100 USN ships visit Singapore yearly and 200 USN personnel are based in Singapore. Also USN maintains a Navy Regional Center in Singapore:
About NCRS and Singapore
Singapore also signed 'The Strategic Framework Agreement for a Closer Cooperation Partnership in Defence and Security' with the United States in 2005.
So by the looks of it Singapore has a far closer relationship to USN than with China as you claim.
What a wonderful way to get thanks.