51
Thousands of fresh US troops headed for Iraq Thursday as British Prime Minister Tony Blair and US President George W . Bush discussed the effort to oust Saddam Hussein , which some senior US military officials warn could last months .
 troops: artifact; Iraq: origin
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: transport 
  Option: victim, artifact, destination, place, origin, vehicle, agent 
Text: {0} 
Answer:
 troops: artifact; Iraq: origin