You have to apply for a US visa prior to departure for any purpose of travel.
No, a Chilean citizen does need a visa to travel to the UK. You can check by yourself by going to http://www.ukvisas.gov.uk/en/
Yes, a Venezuelan citizen can obtain a US visa, but they must meet the requirements set by the US government, such as having a valid reason for travel and meeting the necessary documentation and financial criteria.
Guam is a US Territory, and as such, just like any other US owned soil, a Visa is not required as long as you are a US citizen. Saipan also does not require a Visa to visit.
There are no legal requirements to TOUR the UK. However, you may need an appropriate visa to ENTER the UK.
Depending on the passport you carry you may or may not need a visa. If you are a US citizen and are travelling on a US passport, then, no, you do not need a visa if your stay is shorter than 90 days. As visa requirements change, please visit your local Argentinean Embassy/Consulate for the latest requirements prior to your travels.
As a citizen of New Zealand, you will not need a visa to enter us for visiting or transiting. You need a valid passport (as usual) and perhaps your birth certificate.
Yes, a US citizen needs a visa to travel to Russia.
Sure, there are no restrictions on marriage. However, being married does not automatically change one's visa status or citizenship. Make sure you understand the requirements to become a legal resident so that you are not separated from your spouse by INS!
Belgium participates in the VWP, (Visa Waiver Program) so most Belgian citizens do not need a visa to travel to the U.S.
A Canadian citizen can obtain a working visa for the USA by applying for a specific type of visa, such as an H-1B visa for skilled workers or a TN visa under the NAFTA agreement. They will need to meet the requirements for the specific visa category, have a job offer from a US employer, and go through the application process with the US Citizenship and Immigration Services (USCIS).
Yes, US citizens traveling to Chile for tourism or business purposes for up to 90 days need a visa.
Yes, a Russian citizen can visit the US by obtaining a visa or participating in the Visa Waiver Program.