Mexico's banking regulator said on Thursday it will temporarily step in to manage three financial institutions, CIBanco, Intercam Banco and Vector Casa de Bolsa sanctioned by the U.S. for alleged involvement in money laundering linked to organized crime.

Mexican President Claudia Sheinbaum has responded sharply to U.S. government sanctions blocking transfers from three Mexican financial institutions, saying Washington hasn’t shown evidence of its allegations of money laundering.

The U.S. Treasury on Wednesday prohibited certain transactions with Mexico-based financial institutions CIBanco, Intercam Banco and Vector Casa de Bolsa as part of its new fentanyl sanctions.

Three Mexican financial institutions will be barred from transacting with U.S.-based banks after a U.S. Treasury agency determined that the institutions allowed their networks to aid the illegal fentanyl trade of Mexican criminal organizations.