NO­GALES, Ari­zona — U.S. bor­der agents pa­trolling Ari­zona’s vast and un­for­giv­ing fron­tier are con­fronting crim­i­nal or­gan­i­sa­tions with bil­lion-dol­lar re­sources while op­er­at­ing un­der com­par­a­tive­ly lim­it­ed bud­gets, a dis­par­i­ty of­fi­cials say has be­come one of the biggest chal­lenges in se­cur­ing the bor­der.

Deputy Agent in Charge Rich White said the fi­nan­cial im­bal­ance be­tween Mex­i­can car­tels and U.S. Bor­der Pa­trol op­er­a­tions cre­ates an up­hill bat­tle in an en­vi­ron­ment al­ready de­fined by pun­ish­ing ter­rain and lo­gis­ti­cal ob­sta­cles.

“Our op­er­at­ing bud­get is on­ly in the mil­lions com­pared to the ad­ver­sary in the bil­lions,” White said dur­ing a brief­ing in south­ern Ari­zona dur­ing the For­eign Press Cen­tres Re­port­ing tour, which takes place be­tween May 17 and 23. Jour­nal­ists from around the world, in­clud­ing Pak­istan, In­dia, Ger­many, the Unit­ed King­dom, The Gam­bia, Chile, Colom­bia, Nige­ria, Kenya, Pe­ru and Spain