The proposed U.S.-Mexico border wall will cost at least $21.6 billion and could take more than three years to finish, Reuters reported.
Citing an internal report at the Department of Homeland Security, Reuters reported that the estimated costs were expected to be presented to DHS Secretary John Kelly.
House Speaker Paul Ryan said last month that the project could cost $8 billion to $14 billion. President Donald Trump had previously said the wall could cost $12 billion.
The border wall was one of Trump’s key campaign promises, and his insistence that Mexico would pay for it was extremely popular among his supporters.
Reuters said the report lays out a three-pronged approach to get the wall completed. The phases include the construction of fences and walls covering more than 1,200 miles and finishing by the end of 2020.
According to the report, the first phase would cover 26 miles near San Diego; El Paso, Texas; and a part the Rio Grande Valley in Texas. The second phase would cover 151 miles in and around the Rio Grande Valley; Laredo, Texas; Tucson, Ariz.; Big Bend, Texas; and El Paso. The final phase would cover the remaining 1,080 miles.