Business travelers may enter the United States using a B1, or 'Visitor for Business' Visa. In practice these visas are invariably issued as jointly with B2, or 'Visitor for Pleasure' (i.e. Tourist) visa. This practice means that, if a candidate has an old tourist visa, it may be valid for a planned business trip. For those who come under the visa-waiver scheme, details of which are provided below, there is usually no need to apply for a visit visa at all if the candidate wishes to visit the US for three months or less.While in the US as a business visitor, an individual may:Conduct NegotiationsSolicit sales or investmentDiscuss planned investment or purchases.Make investments or purchasesAttend Meetings, and participate in them fully.Interview and hire staff.Conduct research.The following activities require a working visa, and may not be carried out by business visitors:Running a business."Gainful employment".Payment by an organization within the US.Participating as a professional in entertainment or sporting events.Obviously there is a considerable 'gray area' in between what definitely is allowed and what definitely isn't. It is advisable to err on the side of caution when bringing overseas persons into the USA on business visitor visas. However, in certain strictly limited cases, paid employment may be possible using a 'H1B'Those entering on visitor visas will generally be granted 6 months admission (the maximum allowable is one year) on entry. It may be possible to obtain a six-month extension to the visit visa as long as the candidate will be maintaining visitor status, and there are good reasons to do so. It is sometimes possible to change status to another longer - term visa whilst in the US as a visitor, as long as the candidate advised the relevant US Embassy or Consulate of this possibility beforehand, or there was no pre-conceived intent to do so.NB: Visit visas should generally be applied for in a country of which the candidate is a Citizen or permanent resident. Applications made in other countries often run a high risk of being turned down. The most common reason for refusal of B1/B2 visas is the applicant showing insufficient evidence of social, family or economic ties to his/her country of residence that would ensure that s/he would return there following the visit to the USA.Answer: You are allowed to travel outside of the United States while your permanent resident petition ois being reviewed so long as your B1/B2 visa is current.