You don't need a visa if you have a biometric (electronic chip) passport and you are staying in the USA for 90 days or less for business or pleasure travel. Otherwise yes you need a visa.
An American citizen does not need a Visa to go to Romania unless they plan on staying there. They just need a passport.
No
no
yes Nepalese they need visa to go Maldives but they will get visa upon Arrival
lebanese citizens need a visa to go anywhere
Yes, you do.
A passport and a visa.
If you are US, Canadian or European citizen you can enter Mexico without the need of a visa.
If you are an American citizen, you have to get a visa to go anywhere out of the country. If you are already out of the country, you probably already got a visa to go there if it isn't in North America.
Yes , go Forward
actually, if any citizen need to go any other countries the have to need to be obtain a visa to travel.
No - not if you are a European citizen. If you are American/Canadian you also do not need one if you have signed the Visa Waiver