I think u should use VPN for us Country for all off-page,directory submission,press release,article submission and all the seo activities and ads campaign for USA country
When getting traffic from certain countries you need to focus on things that are exclusive to those countries like buildings, traditions etc...
Advertise on online ad networks that will provide good yet better quality traffic from the US. Depending on your budget, some network provide cost effective bids. You can try Findology. I found new promo codes for Findology.com they're currently offering: 1. FindTech30 Deposit $100 towards PPC or CPV traffic and receive a $30 bonus! 2. Google30 Deposit $100 towards PPC or CPV traffic and receive a $30 bonus! 3. PPC2012 Deposit $100 towards PPC or CPV traffic and receive a $25 bonus!
All you campaign and activities target base on US . Build your backlink from US website, All facebook ads, google ads campaign set target to US. Place your details in US directories and classified. Make your site more open to global and might use US people as photo image in website. Make your site more like US local site. But US is too wide while it better to target with the city or state . It more easy to target from small and niche target.