"Even before I left for the United States, the French media said it was already a failure. That's not at all the case," she told a throng of French journalists.
Le Pen, of the anti-immigrant National Front party, had an agenda filled more with visits to centres of power like the US Capitol than with meetings with political leaders.
But the office of Republican representative and presidential hopeful Ron Paul said he had a "quick private meeting" with Le Pen earlier on Wednesday.
"They primarily discussed monetary policy and the gold standard," spokeswoman Rachel Mills told AFP.
Le Pen declined to identify other US lawmakers with whom she was due to meet, out of fear that they would cancel due to "pressure."
Asked whether her far-right views upset Americans, Le Pen said that instead "the French government is very upset with my presence here and is seeking to minimize the impact of my visit by any means possible."
Le Pen, who is due to visit UN headquarters on Thursday, accused France's ambassador there, Gerard Araud, of having sent "a rather strong message" that she was not "welcome."
After several changes to her program, Le Pen was due to meet with a "representative of the black community," whose identity was not revealed, before visiting Congress, followed by IMF headquarters and the National Press Club.