JEFFERSON CITY, Mo. (AP) – U.S. Sen. Claire McCaskill says that President Donald Trump’s proposal to build a wall along the Mexican border might not be the most effective solution for keeping out immigrants seeking to enter the U.S. illegally.

The Missouri Democrat said in a conference call Tuesday that she toured the border by air, land and water in Texas last week and went to briefings with U.S. border security officials. She says border patrol officials expressed a need for better technology and updated facilities.

The senator said extending the wall would require the “controversial” acquisition of private lands by the government.

McCaskill encouraged lawmakers to consider technological investments to close gaps and find people who have overstayed after their work or education visas expire.