The UN refugee agency said on Friday it needs $145 million (110 million euros) in extra funds to help thousands fleeing fighting in Sudan's Blue Nile and South Kordofan states.

The sum would cover the basic needs of up to 185,000 Sudanese people who are continuing to flock to Ethiopia and South Sudan, UNHCR spokesman Adrian Edwards said.

It will be used to build and maintain more refugee settlements, improve road access and organise relief supplies ahead of the rainy season beginning in April.

The UN has registered more than 30,000 refugees in the two neighbouring countries so far this year -- "a pace of arrival not foreseen during the regular 2012 planning cycle," said Edwards.

Since June 2011, heavy fighting between Sudanese government forces and the Sudan People's Liberation Movement-North (SPLM-North) in South Kordofan and Blue Nile states has forced more than 130,000 refugees into Ethiopia and South Sudan.

In South Sudan UNHCR has moved about 20,000 refugees from unsafe border sites since early January, taking them to four new settlements.

In Ethiopia's Assosa region, the pace of relocation from border areas has also accelerated in recent weeks due to fighting in Blue Nile and the end of the harvest season for refugee farmers living near the border.

UNHCR said it expects more arrivals over the coming months, with clashes continuing and humanitarian conditions deteriorating in the conflict zones.