Ryan's visit comes as US President Donald Trump's plan to reshape the US immigration system along with Congress's role in financing the plan take centre stage in the new administration.
A delegation of US lawmakers led by Republican House Speaker Paul Ryan has visited the US-Mexico border on Wednesday.
Rio Grande Valley in Texas is an area considered ground zero for immigration and border security.
The visit is expected to give Ryan and other politicians a first-hand view of who's crossing the border.
This comes as the Congress debates how to pay for the building of a wall along the border, which was one of Trump's central campaign promises.
He was scheduled to visit an immigration detention facility, take an aerial tour of the area and a tour of Rio Grande River.
Mexican President Enrique Pena Nieto in January had condemned US President Donald Trump's decision to order the construction of a border wall between the two neighbouring countries.
TRT World spoke to Republican party county leader Sergio Sanchez for the details of immigration and border security.
Trump has vowed to force Mexico to pay for the wall, but Pena Nieto and other Mexican officials have repeatedly said Mexico will not pay.
Trump has also suggested that Washington could impose a 20 percent tax on goods from Mexico to pay for a border wall, which would send the peso tumbling and deepen a crisis between the two nations.
TRT World's Tetiana Anderson has the latest from the US-Mexico border.