The US Attorney's Office for the District of Columbia said in a statement Thursday that Ayad Fatafta and Kifah Ghanimat face federal charges of murdering a US national outside the United States.
They are charged in the 2010 murder of 44-year-old tourist Kristine Luken.
The two were convicted in an Israeli court of murder for stabbing Luken and a friend who were hiking together. The other victim survived the attack.
Fatafta was sentenced to a life term in prison plus 20 years. Ghanimat was sentenced to two life terms and 60 years for the attack on Luken and another crime.
A court document filed in the United States says Ghanimat told Israeli authorities that Fatafta told him "that they were going to kill every Jewish person that they met." Luken was a Christian missionary; her friend, a licensed tour guide, was wearing a Jewish Star of David at the time both were stabbed.
Mohammed Fatafta, Ayad Fatafta's brother, a Palestinian police officer in the West Bank, said the family was not aware of the U.S. charges. But he said the case was unfair and made no sense when his brother has already been convicted and sentenced to life in prison plus 20 years.
"The crime took place in Israel and the trial took place in Israel too. That's enough," he said.
Meg Luken, Kristine Luken's step mother, said in a brief telephone call with The Associated Press on Thursday that the family was "very encouraged" by the filing of the charges but didn't want to make any further statement.
Luken's friend, Kay Wilson, the British-born Israeli who was wounded in the attack, praised the U.S. decision.
In a statement posted on her Facebook account, she called it "the best news" she's had in six years.
"Although the prisoners are in an Israeli jail, should my government ever decide to let murderers free again in a prisoner exchange, these cold-blooded savages will not be released. Instead, they will be shipped off to the USA to stand trial there. I'm so relieved, I'm near to tears," she wrote.