The US State Department is set to begin revoking the passports of thousands of Americans who owe substantial unpaid child support, according to officials. Revocations will begin Friday and will initially focus on parents who owe $100,000 or more in past-due child support. That group includes about 2,700 passport holders, according to figures supplied by the Department of Health and Human Services. Under Federal law, anyone with more than $2,500 in unpaid, court-ordered child support can be denied a passport or have an existing one yanked, according to a release by the State Department Thursday. Officials said the department is expanding coordination with the Department of Health and Human Services to include parents above that threshold. The enforcement push is intended to pressure delinquent parents to comply with court-ordered child support obligations, officials said. The US State Department will begin revoking passports from Americans with large unpaid child support debts.…