MEXICO CITY (Reuters) - Mexico’s Cemex, one of the world’s largest cement producers, is open to providing quotes to supply the raw materials for U.S. President Donald Trump’s promised border wall, its chairman told Reforma newspaper on Wednesday.

Trump repeated on Tuesday a vow that he would soon start building a barrier along the nearly 2,000-mile (3,200 km) U.S.-Mexico border to prevent illegal immigrants and drugs crossing north.

“We will gladly do it,” Cemex board chairman Rogelio Zambrano told the newspaper, when asked if the company would provide a estimate for supplying cement to companies that end up working on the controversial project, potentially worth billions of dollars.

Cemex shares rose more than 6 percent and were the highest performing on the Mexican exchange on Wednesday, outperforming the IPC index which was up 1.3 percent. It was the best one day percent gain in nearly a year for Cemex.

Zambrano said it was not known which companies might participate or the likely demand for cement for the wall, the newspaper reported.

The U.S. Customs and Border Protection agency said on Friday it will release a request on or about March 6 asking companies for prototype ideas for a wall to be built near the U.S.-Mexican border.

A Cemex spokesman echoed Zambrano’s comments, adding that the company provided construction materials rather than engaging in construction in the United States and no one had approached Cemex asking it for materials.

“If one of our clients asks us for a quote for materials, we have the responsibility to do it,” the spokesman said.

Trump has consistently said Mexico will ultimately pay for the new wall, while Mexican officials have firmly rejected that idea.

Much of the border already features some kind of physical barrier in addition to other security measures.