UN says 6.6m Syrian children now need aid

The number of children in need because of the Syrian crisis has risen by a third in the last year, with 6.6 million now needing help.

The UN says 6.6 million children are in need of aid (AAP)

More than six million children affected by the Syria conflict desperately need humanitarian aid, the UN's children's agency says.

UNICEF is warning that despite the spiralling numbers the organisation may have to consider cutting some vital services because of a lack of funding.

Some 6.6 million children now need help in the region, the agency said on Friday, a figure that has gone up by a third, or about two million, since June 2013.

"That's an astonishing number and it's one that is rising very, very fast," UNICEF spokesman Simon Ingram told reporters in Geneva.

The organisation has so far only received 37 per cent of the $US770 million ($A833 million) it needs to cover its services until the end of the year for Syrian children both inside the country and living as refugees in neighbouring countries.

"There is actually a very real risk that as a result of this funding crisis and unless the money does come in we will be forced to discontinue some of the critical services that we are providing," Ingram said.

UNICEF is especially worried - given the hot start to the summer in the region - that it may soon have to halt water and sanitation services in Iraq, Lebanon and Jordan, which along with Turkey are hosting the lions share of the Syrian refugees in the region.

Ingram stressed the potentially dire consequences of such a move in places where diseases could easily spread.

Of particular concern is polio, with thirty-six cases of the crippling and potentially fatal disease discovered in Syria this year.

Since the Syria conflict erupted in March 2011 more than 162,000 people have been killed and millions displaced.