Texas' top Senate Republicans on Monday upped the urgency on federal policymakers to do something about the Zika virus.

Lt. Gov. Dan Patrick and state Sens. Charles Schwertner, R-Georgetown, and Jane Nelson, R-Flower Mound, penned a letter to the state's congressional delegation and the Obama administration, saying Texas desperately needs federal funding to combat the Zika virus after recent floods. Without federal assistance, they said, Texas could face "potentially devastating effects."

"States and local health departments need the assistance now," the state lawmakers wrote. "Implementation of the state's response is hampered by the uncertainty of federal funding."

In pregnant women, the Zika virus has been linked to microcephaly, a birth defect causing babies to have abnormally small heads and serious developmental problems.

Congress is expected to take up a funding bill for Zika prevention this week. The Obama administration in February asked U.S. lawmakers to set aside $1.9 billion to combat the mosquito-borne disease, but that's reached a three-month stalemate as Republicans in the U.S. House and Senate hammer out the details of a proposal that would spend less.

A bill offered in the Senate would allocate about $1.1 billion; a House proposal offered roughly $620 million.

Notably, the state lawmakers' letter did not take sides in the congressional debate.

"We urge you to help ensure a coordinated and robust response by the federal government to combat the spread of Zika," they wrote.