US President-elect Barack Obama will introduce rules to restrict the role of lobbyists as he shapes his administration, says a senior official.
Transition chief John Podesta said Mr Obama would introduce "the strictest and most far reaching ethics rules of any transition team in history".
He promised the "most open and transparent" ever handover of power.
Mr Obama's defeated Republican rival John McCain, meanwhile, cracked jokes about his defeat on a US talk show.
In his first post-election TV interview, Arizona Senator McCain said that since being trounced by Mr Obama in last week's election he had been "sleeping like a baby".
"I sleep two hours, wake up and cry," he added, repeating a gag he made after losing to George W Bush during the Republican primaries in 2000.
Appearing on NBC's The Tonight Show with Jay Leno, Mr McCain ruled out another run for the presidency, saying: "I wouldn't think so, my friend. It's been a great experience and we're going to have another generation of leaders come along."
He also said his running mate Sarah Palin inspired people and predicted she "would play a big role in the future of this country".
Both Mr Obama, who takes office on 20 January, and Sen McCain railed against lobbyists during the election campaign, accusing them of peddling favours and influence to sway Capitol Hill lawmakers in a culture of corruption.
At a briefing in Washington, Mr Podesta told reporters Mr Obama had "pledged to change the way Washington works and curb the influence of lobbyists".
Interest groups have been offering recommendations on cabinet-level appointments to the Obama transition team.
But Mr Podesta gave no indication of when the key posts of treasury secretary and secretary of state would be filled.
Under the new measures, Mr Obama will not allow lobbyists actively petitioning the federal government to work with the transition, said Mr Podesta.
The guidelines will also prevent anyone who has acted as a lobbyist over the last 12 months from working on any policy area in the transition in which they had been active.
He added that anyone who works on the transition and then becomes a lobbyist will be barred from approaching the administration for 12 months in the area in which they worked.
New details emerged, meanwhile, in Mr Bush's first post-election interview, of Monday's visit by Mr Obama and his wife Michelle to the White House to meet the outgoing president and first lady.
Mr Bush told CNN that after their policy discussion, his successor had wanted to check out the future bedrooms of his two daughters.
"It was interesting to watch him go upstairs, and he wanted to see where his little girls were going to sleep," Mr Bush said.
Mr Bush also told CNN: "I know I'll miss certain things about the presidency. I also know I'm looking forward to getting home, so I've got mixed emotions."
Meanwhile the Associated Press news agency reported First Lady Laura Bush was in the early stages of talks with publishers about penning a memoir on her time in the White House.