U.S. Consulate General Hong Kong and Macau – American Citizens Services:
https://hk.usconsulate.gov/u-s-citizen-services/
Apply for a U.S. Visa:
http://ustraveldocs.com/hk (Call Centre: 852 5808 4666)
Macau Day – U.S. Consular Services in Macau by Appointment:
https://hk.usconsulate.gov/sm-macau-day/
U.S. Commercial Service in Hong Kong:
https://2016.export.gov/hongkong/
United States Department of Agriculture in Hong Kong:
http://www.usda.gov/wps/portal/usdahome
Macao Trade and Investment Promotion Institute (IPIM):
http://www.ipim.gov.mo
Macau Government Tourist Office:
https://www.macaotourism.gov.mo/en/
Other Macau Government official websites:
https://www.gov.mo/en/