To travel to the US they will have to get a US Visa, you can contact them for even more information
[email protected]
Here are some warnings by the US embassy in Ghanna
US Diplomatic Mission to Ghana: Press Release, Public Affairs Section (http://usembassy.state.gov/accra/wwwhdating.html)
US Diplomatic Mission to Ghana: Press Release, Public Affairs Section (http://usembassy.state.gov/accra/wwwhwebfraud.html)
And the following is an official govermnet warning
ROMANCE SCAMS
Before you send any money to Ghana, please take the time to be very well informed.  Start by considering the fact that scams are common enough to warrant this warning.  Next, look over this partial list of indicators.  If any of them sound familiar, you are likely the victim of an internet scam.
-You met a friend/fiancé online
-You've never met face to face
-Your correspondent professed love at warp speed
-Your friend/fiancé is plagued with medical problems requiring loans from you
-You are promised repayment upon the inheritance of alluvial gold or gems
-You've sent large sums for visas or plane tickets but the person cannot seem to make it out of Ghana
-When your friend does try to leave the country, h/she is detained by immigration officials demanding payment or bribes
-Your correspondent consistently uses lower case “i's” and/or grammar not in-keeping with their supposed life station or education level
Cases bearing these and other hallmarks have all proven to be scams intended to separate sympathetic people from their money.   We advise Americans not to send money to people they have never actually met.  In the event you do lose money, be warned that your chances of getting it back are almost nil.  This type of crime is not a priority for local police, even if they had the resources to tackle it.  The Embassy can offer a sympathetic ear but, often, little else. Victims can report the scam on www.ic3.gov and might also consider alerting the dating website on which the scammer was encountered.
Some facts and resources:
-It is very difficult to recover money sent to these scammers as they work from internet cafes and are entirely portable and elusive. 
-Many Americans have reported losing thousands of dollars through such scams.
-The anonymity of the Internet means that the U.S. citizen cannot be sure of the real name, age, marital status, nationality, or even gender of the correspondent. In the majority of cases reported to the embassy, the correspondent turned out to be a fictitious persona created only to lure the U.S. citizen into sending money.
-U.S. citizens may refer to USCIS Home Page (http://uscis.gov) or Welcome to Travel.State.Gov (http://www.travel.state.gov) for authoritative information about the immigration process and the true costs involved.
-This link leads to a comprehensive brochure on financial scams: http://travel.state.gov/pdf/international_financial_scams_brochure.pdf
- If the correspondent provides an image of a purported U.S. visa as proof of intention to travel, the U.S. citizen may contact the United States Embassy in Accra at
[email protected] to ascertain the validity of the visa.
 
-In the aftermath of a scam, some people have found support and camaraderie at a Yahoo group started by and for scam victims. Participants have reported that the group helps underscore the breadth of the problem and allows people to see they are not alone. romancescams : ROMANCE SCAMS (http://groups.yahoo.com/group/romancescams) [please note this group is in no way affiliated with or endorsed by the U.S. government.]