Citibank to Seek Stay of Argentina Ruling, Lawyer Says

A legal ruling prevents a bank from forwarding a $5 million payment to Argentine bondholders. Citibank claims Argentina has threatened sanctions, including nationalization, if it doesn't pass the interest payment on $8.4 billion in bonds issued under Argentine law.

What potential consequence did Citibank face if Argentina failed to pass the interest payment?

Under what law were the bonds issued?