The United Nations says Fiji's government has become the first to agree to provide troops specifically to protect UN officials in Iraq.
Fijian soldiers have been sent to trouble-spots before
The 35 UN officials in Baghdad are currently protected by troops from the US-led multinational force.
But the BBC's Susannah Price at the UN says there are fears that this could make them more of a target.
The UN is very worried about the safety of its personnel after the bombing of its Baghdad headquarters last year.
The suicide attack in August 2003 killed 22 people including the top UN envoy in Iraq, Sergio Vieira de Mello.
That and other attacks prompted UN Secretary General Kofi Annan to pull all non-Iraqi staff out of Iraq.
The UN is coming under increasing pressure to send more staff to Iraq ahead of the expected poll in January.
"We call on the UN to accelerate their support and their presence in Iraq because time is short and we need a genuine engagement and involvement from the international organisation to help us conduct these crucial elections," Iraqi Foreign Minister Hoshyar Zebari said on Wednesday.
Mr Annan said this week that governments who were asking him to send civilian staff to Iraq were not providing troops to protect them.
But on Wednesday UN spokeswoman Maria Okabe announced that 130 Fijians would provide security details for senior UN officials and a guard unit to protect UN facilities in Baghdad.
"These contributions are critical to the UN's efforts to strengthen the security arrangements for its personnel in Iraq," she said, quoted by the Associated Press news agency.
"This would make it possible for the United Nations to consider expanding its activities in Iraq as circumstances permit."
Australia has already agreed to provide training and equipment for the Fijians.
Our correspondent says the UN needs to be seen as independent in Iraq and wants to avoid being closely associated with the US-led multinational force.
But UN staff will continue to depend on this force for much of its protection even after the Fijian troops arrive.
The South Pacific country has a long and proud history of sending its forces to the world's trouble-spots.
The most recent deployment was in the Solomon Islands as part of the Australian-led intervention.
Fijian soldiers have also served with the UN in East Timor and Lebanon.
More than 1,000 Fijians are currently serving in the British Army, some of them in Iraq.
Some former soldiers from Fiji have been working as mercenaries in the region.