Secretary of State Rex Tillerson, right, meets with Mexican Foreign Secretary Luis Videgaray Caso at the State Department on Aug. 30. (Alex Wong/Getty Images)

Secretary of State Rex Tillerson thanked Mexico on Wednesday for offering help as the United States copes with the effects of Hurricane Harvey, but he did not say whether the United States will take its neighbor up on the offer.

“They've offered a wide range of assistance,” Tillerson said before a previously scheduled meeting with visiting Mexican Foreign Minister Luis Videgaray Caso.

“It's very generous of Mexico to offer to help at this very, very challenging time for our citizens down in Texas” and in Louisiana, where the storm has moved, Tillerson said.

“We are here to help. We are neighbors, we are friends, and that's what friends do,” Videgaray replied as he shook hands with Tillerson at the State Department.

Accepting Mexico's offer could put President Trump in an awkward spot. He has insisted that Mexico would pay for a new border wall he had promised as a candidate, perhaps through some sort of reimbursement. Mexican officials say the aid offer is a neighborly gesture that does not change their country's insistence that it will never pay for a wall.

“With Mexico being one of the highest crime Nations in the world, we must have THE WALL. Mexico will pay for it through reimbursement/other,” Trump tweeted Sunday.

Texas Gov. Greg Abbott and the Federal Emergency Management Agency are coordinating with Mexico on the aid offer, Tillerson said. Mexico is reportedly offering relief supplies, equipment and personnel to help flood victims in next-door Texas.

Tillerson is a native Texan who maintains a home in the state.

The State Department had confirmed the aid offer late Tuesday and said FEMA would determine whether there was a need for it.

“It is common during hurricanes and other significant weather events for the United States to be in close contact with our neighbors and partners in the region to share data and cooperate as needed and appropriate,” the State Department said.

“When the State Department receives a formal offer of assistance from a foreign government, we work with FEMA to determine the best way forward.”

The Houston area received more than 50 inches of rain over four days, causing unprecedented flooding and killing at least 22 people.

Now a tropical storm, Harvey is the biggest rainstorm in the history of the continental United States and poses a continued flooding threat in Louisiana.

Mexican officials have said their country stands ready to repeat the kind of assistance it offered after Hurricane Katrina in 2005. Then, Mexico provided troops, food and medical supplies for residents of New Orleans. Some troops remained in the United States for weeks as part of the humanitarian aid.

The State Department said FEMA must first evaluate whether the U.S. government can cover the need. “In the event that federal assets are not available to meet a specific request, FEMA works with the State Department to coordinate and evaluate any offers of support from a foreign nation that may assist in meeting that need.”