The United States and Colombia are nearing agreement on expanding the U.S. military’s presence in this conflict-torn nation, potentially basing hundreds of Americans in a central valley to support Air Force drug interdiction missions.

Both sides say they hope a fifth round of talks slated for later this month in Bogota will seal a 10-year lease deal. Two of the Colombian ministers involved were to answer questions about the talks at a public hearing Wednesday following complaints about secrecy surrounding the negotiations.