This is almost backwards. Nazi Germany was certainly eager to gain access to Mexican oil, this much seems true, and unsurprising given their strategic needs. But the United States certainly did not request that Mexico expropriate American-owned oil companies, which would be a very bizarre step to take indeed. The oil companies in Mexico were owned by American and British firms. The proximate cause of Lázaro Cárdenas' nationalisation program was a reaction to the labour disputes on the oil fields (notably, the unwillingness of the oil companies to abide by the decisions of the Mexican Supreme Court) not the grand plan of a mastermind, nor a reaction to some conspiracy with the Americans.

Once the oil industry was nationalised, oil companies successfully lobbied the US government for action. The US government did demand compensation for the expropriated property, which was eventually given under fairly generous terms. Pressure from the UK was more stringent, and they tried to embargo Mexican oil. Diplomatic relations between Britain and Mexico countries broke down, though eventually the British interests were also compensated from 1946, under American pressure. They exercised this pressure in 1938 by via suspending US Treasury purchases of Mexican silver. This would be a very odd step to take, if the nationalisation had been done at the behest of the US in the first place!

While there were some attempts to circumvent British sanctions by bartering oil to Germany, Italy and Japan, these were relatively short lived, and in any case triggered by the sanctions themselves. This would be strategic nonsense, for the US to encourage nationalisation, then punish Mexico for an action they themselves encouraged, and then allow a close ally to maintain an embargo that drove Mexico to increase export oil to Axis countries. It just doesn't make any sense.

Indeed, fear of driving Mexico into Axis hands was one reason that the US response was limited a demand for compensation, backed up by sanctions, rather than cutting diplomatic ties, or a military intervention. FDR did not particularly favour the oil interests, and his "good neighbour" stance meant maintaining friendly relationships with Latin America. (From Coolidge onwards there had been a break from the old style of pre-WWI rampant interventionism of sending in the Marines as a reflex against any economic harm to American companies or bondholders.) In any case, the Cárdenas government had no great plans to burn bridges with the United States, or to join up with distant and dubious allies like the Axis powers. They provided compensation to the American, and eventually British companies, and the matter was resolved.