The Defence Secretary's annoyance at the White House emerged during an interview with London's Financial Times newspaper - a rare display of public pique within President Bush's disciplined inner circle.
In the interview, Rumsfeld sounded annoyed that Condaleeza Rice, who heads the National Security Council, had decided to draw attention to a memo establishing the reorganisation by briefing The New York Times.
Under pressure to bring stability to Iraq, President Bush announced on Monday a major reorganisation of US efforts to bring control to Iraq, headed by Rice, and including representatives from the State Department.
Analysts have speculated this means that Rumsfeld's Pentagon is being sidelined from post-war Iraq.
Rumsfeld said he did not know Rice was writing the memo, but admitted he wrote memos himself that colleagues did not know about until they received them.
He said the memo should not be classified and should be released.
But answering questions from reporters in Colorado Springs, Rumsfeld said he was "not at all" upset about the memo.
"It's not a problem or an issue," Rumsfeld said, expressing surprise that reporters were asking him about the issue.
Bush's poll ratings are falling
over the Iraq occupation
White House officials said Bush retained complete confidence in Rumsfeld, that his authority had not been diminished, and that the Pentagon remained the lead agency in Iraq.
But the move was perceived in Washington as giving the State Department a greater say in post-war reconstruction in the country.
"What it means is that, at least in the policy formulation stage, other agencies are going to have a bigger voice than they had up to this point," said Ivo Daalder, a defence analyst at the Brookings Institution think tank.
"And in that sense, by definition you're seeing a diminution of Rumsfeld's ability to control that process."
Rumsfeld's pique has come at a time when the White House is launching an aggressive public relations push to bolster declining support among Americans for the Iraq occupation.
President Bush used a $14 million fund-raiser on Wednesday night to reassure Republican campaign contributors that "America did the right thing" in Iraq and that the hunt for weapons of mass destruction was well underway.
"There's a lot more to investigate," he told 2000 Republican donors. "Yet it is now undeniable - undeniable - that Saddam Hussein was in clear violation of United Nations Security Council Resolution 1441," he said, citing evidence the top CIA weapons hunter presented this month.
"Iraq is free. America is more secure," he said.