N.H. Rev. Stat. Ann. § 106-P:1

Neither the state nor any county, municipality, or other political subdivision of this state shall prohibit or impede any state, county, or local law enforcement agency from applying for entry or entering into an agreement with the United States Immigration and Customs Enforcement to participate in a federal 287(g) program pursuant to 8 U.S.C. section 1357(g).