WASHINGTON - The White House said on Monday that it will ask the US Congress for permission to redirect some money set aside for Ebola-related projects for its response to the Zika virus, but said it would primarily need new funding to address the outbreak.

President Barack Obama has asked Congress for more than $1.8 billion to fight Zika, but several top Republican lawmakers have said the administration should instead draw from funds not yet used for public health projects aimed at the Ebola virus.

"The magnitude of the Zika outbreak primarily requires new resources to ensure it is adequately addressed," White House budget director Shaun Donovan said in a letter to Representative Hal Rogers, the top Republican appropriator in the House of Representatives.

But the White House also would like permission to put unused Ebola money toward Zika projects to "give us the flexibility to respond to Zika needs beyond what we have so far identified," Donovan said in the letter.