Mexican Finance Ministry says it has not received evidence to support claims against CIBanco, Intercam and Vector banks.
The United States has imposed sanctions on three Mexican banks, alleging they had been used to launder money for drug cartels.
On Wednesday, the US Department of the Treasury tied the banks – CIBanco, Intercam Banco and Vector Casa de Bolsa – to the cross-border trafficking of the deadly synthetic drug fentanyl.
It accused them of playing “a longstanding and vital role in laundering millions of dollars on behalf of Mexico-based cartels and facilitating payments for the procurement of precursor chemicals needed to produce fentanyl”.
The sanctions are part of a wider pressure campaign by the administration of US President Donald Trump against Latin American gangs, criminal networks and drug traffickers.
That campaign has included designating several groups as “foreign terrorist organisations” and using tariffs to pressure Mexico’s government to increase enforcement of irregular traffic across the border.
In a statement, the Treasury Department said the banks were the first to be targeted under new pieces of legislation – the Fentanyl Sanctions Act and the FEND Off Fentanyl Act – passed to expand its ability to target money laundering related to opioid trafficking.
The sanctions would block transfers between the targeted Mexican banks and US banks, although it was not immediately clear how far-reaching the limits would be.
In a statement, Secretary of the Treasury Scott Bessent accused the banks of “enabling the poisoning of countless Americans by moving money on behalf of cartels, making them vital cogs in the fentanyl supply chain”.
But Mexico’s Secretariat of Finance and Public Credit responded to the sanctions by saying it had yet to receive conclusive evidence justifying them.
“We want to be clear: If we have conclusive information proving illicit activities by these three financial institutions, we will act to the fullest extent of the law,” the Finance Ministry said.
“However, to date, we have no information in this regard.”
CIBanco did not immediately respond to the allegations. The US Treasury Department accused it of being connected to money laundering by the Beltran-Leyva Cartel, the Jalisco New Generation Cartel (CJNG) and the Gulf Cartel.
Intercam, which is also accused of having connections to the CJNG cartel, also did not respond.
Meanwhile, the brokerage firm Vector, which was linked to money laundering by the Sinaloa Cartel and Gulf Cartel, said the US claims tying its operations to drug traffickers were false.
“Vector categorically rejects any accusation that compromises its institutional integrity,” the company said in a statement, adding that it would cooperate to clarify the situation.