All visitors to American Samoa require a valid passport, return ticket or onward ticket and sufficient funds to support their stay. US Citizens and US Nationals do not require a visa and may enter and leave freely. Australian, New Zealand and citizens of the United Kingdom upon entering American Samoa are issued a 30 day permit under the US Visa Waiver Program. All other international passport holders intending to visit American Samoa for business or holiday are required to apply for an entry visa.
For further information contact the Attorney General's Office, phone +1 (684) 633-4163. Or visit the Immigration Office website here.
Don't even think about bringing drugs to American Samoa. The customs officers are highly trained to spot drug carriers. There are dogs at the airport and post office that reliably find drugs. The penalties for drug smuggling, possession and use are absolutely horrendous. Marijuana is not legal for any purpose.