Liberia has been particularly hard hit by the epidemic that has swept relentlessly across the region since March, accounting for almost half of the 1,427 deaths.
In recognition of the deteriorating situation, neighbouring Ivory Coast announced it had closed its borders with Liberia and Guinea in a bid to protect its citizens.
"Ebola in Liberia must be addressed to ensure a stable economy, future and society," said Karin Landgren, UN Secretary-General Ban Ki-Moon's special representative for the country said.
Her comments were echoed by David Nabarro, the UN's new pointman on Ebola, who arrived in the region on Thursday to tour the Ebola-hit countries of Liberia, Sierra Leone, Guinea and Nigeria.
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Nabarro, a British physician tasked with coordinating the global response to the worst-ever outbreak of the deadly virus, said the UN would "ensure that adequate resources are given to sectors that need it most".
A day earlier, the World Health Organization (WHO) warned it could take "several months" to bring the epidemic under control.
Their visit has coincided with a surge in new cases of Ebola in the region, as affected countries struggle to contain the spread of the killer virus.
The WHO said Friday that the death toll had risen to 1,427 out of more than 2,600 cases -- with 77 succumbing to the disease between August 18 and 20.
A British national who lives in Sierra Leone has tested positive for Ebola, the first British citizen to have contracted the disease, according to officials.
He was reportedly set to be flown back to Britain for treatment in the next couple of days. The Department of Health did not immediately respond to a request to confirm the report.