Because of the possibility that deserters have been issued with arrest warrants back in the United States and pursuant to those two agreements above, they are liable for arrest in Canada unless they legalize their status. This can be done by pursuing a refugee claim, about which the Immigration and Refugee Board of Canada (IRB) will hold a hearing and determine the validity of the claim. If refused, the claimant can appeal to the Federal Court, Federal Court of Appeal, and finally the Supreme Court of Canada, if leave is granted.