US President George W Bush has named retired Navy Vice Admiral Michael McConnell as the new US National Intelligence Director.
Michael McConnell's nomination must be approved by Congress
Mr McConnell will take over the leadership of the US's 16 intelligence agencies from John Negroponte.
Mr Negroponte is to become the deputy to Secretary of State Condoleezza Rice.
The changes come just days before Mr Bush is expected to announce a change in military strategy in Iraq in order to tackle the continuing violence.
The expected policy shift follows a recent report from the Iraq Study Group, which said that US policy in Iraq was not working, and a Republican bruising in mid-term elections in November, blamed partly on the White House's handling of the conflict.
BBC world affairs correspondent Nick Childs says the reshuffle puts fresh faces into key positions, perhaps helping to mask the fact that the actual policy changes Mr Bush is expected to unveil may not be as radical as many would like.
In making the announcement, Mr Bush said: "Each of them will do good work in their new positions and it is vital that they take up their new responsibilities promptly."
The nominations must first be approved by the Congress, which opened a new session on Thursday with the Democrats in control of both chambers for the first time in 12 years.
"I would hope that they would be confirmed as quickly as possible," Mr Bush said.
Mr Negroponte has in effect taken a demotion to move
Speaking of his nomination, Mr McConnell said: "I plan to continue the strong emphasis on integration of the community to better serve all of our customers.
"That will mean better sharing of information, increased focus on customer needs and service, improved security processes and deeper penetration of our targets to provide the needed information for tactical, operational and strategic decision making."
The changes are part of a White House re-shuffle which began with Donald Rumsfeld quitting as defence secretary after the mid-term elections.
The post that Mr Negroponte will fill at the state department has been vacant since July 2006.
"It will be a great privilege for me to come home to the department where I began my career and rejoin a community of colleagues whose work is so important and of whom the nation is so justly proud," Mr Negroponte said.
Top brass changes
A career diplomat, Mr Negroponte has a long history of working with the US state department, a role he greatly enjoys, according to the BBC's Matt Frei in Washington:
He has taken an unusual step, in effect taking a demotion to return to the department that he loves, the state department, our correspondent says.
Mr Bush is also set to make a number of key changes in the US military leadership as part of his fresh strategy for Iraq, officials say.
The Pentagon confirmed on Friday that it was recommending that Adm William Fallon replace Gen John Abizaid as head of Central Command for Iraq and Afghanistan.
And Lt Gen David Petraeus was being recommended to take over from Gen George Casey as the leading ground commander in Iraq, Defence Secretary Robert Gates said.
Adm Fallon is currently the top military commander in the Pacific and, if confirmed, the move will put a navy man in charge of two land wars.
The BBC's Sarah Morris in Washington says the new strategy could include a deployment of 20,000 fresh troops to be stationed mostly in and around Baghdad with the intention of disarming the militia groups there.
But Mr Bush said he needed to hold further consultations before he outlined the strategy.
His other key change is expected to be the replacement of John Bolton as US ambassador to the UN by current Ambassador to Iraq Zalmay Khalilzad.