WASHINGTON (Kyodo) -- White House officials are actively discussing who will replace Defense Secretary Jim Mattis in the event that he might step down, the Washington Post reported Wednesday.
In a column carried on the paper's online edition, columnist Josh Rogin wrote that Jack Keane, a retired four-star Army general, tops a shortlist for Mattis' potential successor.
President Donald Trump brushed aside the report, telling reporters Mattis is "doing a fantastic job" and that he will stay as the Pentagon chief.
The report came a day after the paper revealed interactions between Trump and Mattis in a forthcoming book by veteran journalist Bob Woodward.
Woodward writes, for example, that after a National Security Council meeting on the Korean Peninsula, Mattis said Trump had the understanding of "a fifth- or sixth-grader."
"The speculation about who replaces Mattis is now more real than ever," Rogin quoted a senior White house official as saying.
"The president has always respected him. But now he has every reason to wonder what Mattis is saying behind his back," said the unidentified official. "The relationship has nowhere to go but down, fast."
Well before the revelations -- which the Pentagon chief dismissed as "a product of someone's rich imagination" -- came to light, many officials inside the White House "had already expected that Mattis would leave his post sometime over the next few months, completing a respectably long two-year stint at the helm of the Defense Department," Rogin wrote.
Retired in 2003, Keane served as vice chief of staff of the Army. "He has strong relationships across the administration and the president likes his TV profile," the senior White House official was quoted as saying.
Other names under discussion inside the White House include Sen. Tom Cotton of Arkansas and Sen. Lindsey Graham of South Carolina, according to the column.