If my uncle from S. Korea gives me a monetary gift, do I need to report that to the US IRS?

By the IRS, do I get gift-taxed on a gift from a foreign individual in the amount of $20K? Also, do I need to report it to the country of origin - if I have a bank account in S. Korea to which he sends the money, would I need to report it to the S. Korean tax authority and would I get taxed for it?