Washington: Ahead of Secretary of State Mike Pompeo's visit to India, the United States on Friday urged the country against buying Russian S-400 systems which may trigger CAATSA sanctions.

"With respect to the S-400, we're urging all of our allies and partners, India included, to forgo transactions with Russia that risk triggering the CAATSA [Countering America's Adversaries Through Sanctions Act] sanctions...This is a time we will be encouraging India to look at alternatives," Sputnik quoted a senior US Department of State official as saying during a conference.