S.O.L.
You need an H1 visa. The contract means SF'All to immigration. Your employer has to jump through a bunch of hoops and request the visa for you, after proving they can find no qualified Americans to do the job. Usual cost out-of-pocket to the employer is $5-$12k USD.
You could just go in on a visa-waiver and change status while over there. Of course, if you're working and you get picked up by ICE, it's immediate deportation, a felony charge, and no reentry to the US for 10 years.