WASHINGTON -- Samantha Power received a mostly cordial reception on Wednesday from senators weighing her nomination as the next United States ambassador to the United Nations, though Republicans pressed her to explain past comments on Israel and Palestine and certain "crimes" she once said had been committed by the United States.
Ms. Power, 42, a former journalist and national security specialist who has written extensively about genocide and humanitarian intervention, appeared to face no serious obstacles to confirmation during the hearing by the Foreign Relations Committee.
On one of the most pressing questions facing the United Nations, she offered a critical verdict, saying, "We see the failure of the U.N. Security Council to respond to the slaughter in Syria a disgrace that history will judge harshly," but she offered few specifics of how she might press the Obama administration for a more vigorous response.
If confirmed by the committee and then the full Senate, Ms. Power would succeed Susan E. Rice, whom Mr. Obama has named as his new national security adviser.
Several key Republican senators, including Bob Corker of Tennessee, the ranking member of the committee, and John McCain of Arizona, offered their support.
"I know you're going to be received very well," Mr. Corker said at the outset of the hearing.
Still, she faced some difficult questions from Republicans, perhaps most notably Senator Marco Rubio of Florida, over controversial remarks and positions she has taken in the past.
His first question was about a 2002 interview in which she suggested that the United States might have to spend billions of dollars to support a "mammoth protection force" and "a meaningful military presence" if Palestinian statehood were ever to be realized.
As she has before, Ms. Power distanced herself from the remarks.
"I gave a long, rambling and remarkably incoherent response to a hypothetical question that I should never have answered," she said.
Ms. Power vowed to fight within the United Nations against what she called "unacceptable bias and attacks against the state of Israel." She went further, saying she would "absolutely" press for Israel to be given its first rotating seat on the United Nations Security Council.
Ms. Power also appeared uneasy, if unsurprised, when Mr. Rubio asked her about a 2003 article on foreign policy in which she argued for "a historical reckoning with crimes committed, sponsored, or permitted by the United States."
In the article in New Republic magazine, she wrote: "A country has to look back before it can move forward. Instituting a doctrine of the mea culpa would enhance our credibility by showing that American decision makers do not endorse the sins of their predecessors."
Although Mr. Rubio pressed her to say what those "crimes" or "sins" were, Ms. Power repeatedly sidestepped.
"I, as an immigrant to this country, think this country is the greatest country on earth," said Ms. Power, whose parents immigrated from Ireland when she was 9. "I would never apologize for America -- America is the light to the world."
This article originally appeared in The New York Times.