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WASHINGTON (Reuters) - Retired U.S. Gen. Colin Powell, a former secretary of state in the Bush administration, on Sunday endorsed Democratic presidential nominee Barack Obama.

In an appearance on NBC’s “Meet the Press,” Powell backed Obama over fellow Republican John McCain, calling the Democratic nominee a “transformational figure” who could be an “exceptional president.”

Powell said he plans to vote for Obama in the November 4 election but does not intend to campaign for the Illinois senator as Obama and McCain enter the final weeks of their battle for the White House.

Powell, who served in the military and government for 40 years, said he is not looking for a job in an Obama administration. However, he said, “I’ve always said if a president asks you to do something, you have to consider it.”

McCain, appearing on “Fox News Sunday,” said Powell’s support of Obama did not come as a surprise and said four other secretaries of state had endorsed him.

In picking Obama over McCain, Powell said either “man would be a good president.”

Powell praised Obama’s “depth of knowledge” and “steadiness,” while he was critical of what he described as McCain’s uncertainty over how to deal with economic crisis.

Powell also voiced concern about McCain’s selection of Alaska Gov. Sarah Palin as his vice presidential running mate.

“She is a very distinguished woman and she is to be admired,” Powell said. “But ... I don’t believe she is ready to be president of the United States.”