The U.S. Department of Health and Human Services fired back at the suggestion by Senate Majority Leader Mitch McConnell (R-KY) that the agency was wasting money on Obamacare outreach that could be used on Zika funding.

“The last person who should criticize HHS for not being focused on Zika is the Senate Republican leader who has refused to compromise in order to get a clean, bipartisan funding bill to the President’s desk,” an HHS spokesperson said in a statement to TPM Friday evening. The statement was in response to a letter McConnell sent to HHS Secretary Sylvia Burwell Friday hounding her on reports of a new outreach campaign for Obamacare enrollment.

In the letter, McConnell demanded details of an outreach campaign to boost Obamacare enrollment reported by the New York Times, while asking why the agency “believes that such funds would be better spent propping up the failed Obamacare exchanges than other important public health priorities – such as preventing the spread of Zika.”

According to the HHS, Affordable Care Act outreach is funded by the Centers for Medicare & Medicaid Services. The agency said the funding cannot be used on Zika-related activities, particularly as the Centers for Disease Control and the National Institutes of Health are not permitted to dip into CMS’ funds.

President Obama, meanwhile, has requested Congress pass $1.9 billion in emergency funds to finance Zika research, prevention and treatment. Initially the House of Representatives approved a much smaller package amounting to $622 million, or about a third of what the White House asked for. Senate Republicans upped their offering to $1.1 billion, but attached to the funding a number of politically-toxic riders including provisions that defunded parts of Obamacare and blocked spending on family planning. Senate Democrats blocked the bill citing the riders as well as the fact that it was still much lower than what the President requested

With Congress’ refusal to approve of new funding, the HHS has already diverted about $670 million from other programs to its Zika response, the agency said. The reallocated funding is expected to run out by Sept. 30, according to Politico, or even sooner, if the current Zika situation worsens and more money is needed immediately.