the attack happened amidprayers. fighters affiliated to i.s.i.l. claimed responsibility for the attacks. u.s. president obama hosted chinese president for a private dinner at the white house. there'll be a former reception on friday. before that they'll discuss two issues that caused friction, cyber security and disputes in the south china sea. here is patty culhane. >> reporter: the white house is talking tough on the eve of xi jinping's state visit raising the possibility of america going through the disputed islands in. the national security visor sent this message. >> the united states of america will sail, fly and operate anywhere that international law permits. >> reporter: president obama had this warning about sign ir attacks on u.s. companies. >> that we consider an act of aggression that has to stop. and we are preparing a number of measures that will indicate to the chinese that this is not just a matter of us being middlely upset. >> the administration floated the idea that they'd sanction chinese companies and people. some believe that