MEXICO CITY — President Jimmy Morales of Guatemala has made no secret of his desire to get rid of a United Nations-backed anti-corruption panel that helped bring down his predecessor.

The commission of international prosecutors has charged Mr. Morales’s brother and his son in a fraud case and it continues to investigate him on campaign finance violations.

Last August, he ordered its director, Iván Velásquez, a Colombian, out of the country, but he was overruled by Guatemala’s highest court. Mr. Morales has met with the United Nations secretary general, António Guterres, to lay out his complaints against Mr. Velásquez and limit the commission’s mandate — all to no avail.

But now he appears to have an ally: Senator Marco Rubio, Republican of Florida, who said this weekend he has placed a hold on $6 million in funding to the International Commission against Impunity in Guatemala.