Lynne Weil said that Lantos, 80, passed away at the Bethesda Naval Medical Center in suburban Maryland.
Lantos, a Democrat who chaired the House Foreign Affairs Committee, disclosed last month that he had been diagnosed with cancer of the esophagus.
He said at the time that he would serve out his 14th term but would not seek re-election in his Northern California district, which takes in the southwest portion of San Francisco and suburbs to the south including Lantos' home of San Mateo.
The timing of the diagnosis was a particular blow because Lantos had assumed his committee chairmanship just a year earlier, when Democrats retook control of Congress. He said then that in a sense his whole life had been a preparation for the job - and it was.
Lantos, who referred to himself as "an American by choice," was born to Jewish parents in Budapest, Hungary, and was 16 when Adolf Hitler occupied Hungary in 1944. He survived by escaping twice from a forced labor camp and coming under the protection of Raoul Wallenberg, the Swedish diplomat who used his official status and visa-issuing powers to save thousands of Hungarian Jews.
Lantos' mother and much of his family perished in the Holocaust.
That background gave Lantos a moral authority unique in Congress and he used it repeatedly to speak out on foreign policy issues, sometimes courting controversy. He was a strong supporter of Israel and a lead advocate for the 2002 congressional resolution authorizing the Iraq war, though he would come to be a strong critic of the Bush administration's strategy there. In 2006 Lantos was one of five members of Congress arrested in a protest outside the Sudanese Embassy over the genocide in Darfur.
Lantos, who was elected to the House in 1980, founded the Congressional Human Rights Caucus in 1983. In early 2004 he led the first congressional delegation to Libya in more than 30 years, meeting personally with Moammar Gadhafi and urging the Bush administration to show "good faith" to the North African leader in his pledge to abandon his nuclear weapons programs. Later that year, President Bush lifted sanctions against Libya.
In October 2007, as Foreign Affairs chairman, Lantos defied administration opposition by moving through his committee a measure that would have recognized the World War I-era killings of Armenians as a genocide, something strongly opposed by Turkey.
