Texas Senator Ted Cruz flew to Mexico with his family for a holiday amid a winter weather crisis that has left millions in his state without power.
In a statement on Thursday, Mr Cruz said that he planned the trip for his daughters, "wanting to be a good dad".
Photos of the Republican lawmaker at an airport emerged on Twitter on Wednesday, fuelling reports that he had left Texas amid the energy crisis.
Texas has seen power and water outages due to the uncommonly frigid weather.
The high profile Republican has drawn quick criticism for taking an international trip amid the weather emergency in his state.
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"People in Texas are literally freezing to death and yet Ted Cruz went on vacation to Cancun," wrote Democratic Congresswoman Pramila Jayapal on Twitter.
pg slotHow has Cruz defended his trip?
In a written statement released on Thursday afternoon, Mr Cruz described an "infuriating week for Texans".
With schools closed in the state, the senator said he booked the vacation for his young daughters who "asked to take a trip with friends".
Mr Cruz did not apologise for making the trip amid the state of emergency in Texas, but said that he and his staff "are in constant communication with state and local leaders to get to the bottom of what happened in Texas."
