British Foreign Secretary Liz Truss said Sunday that “the world’s largest economies are united” in warning Russia that an invasion of Ukraine would have “massive” — though largely undisclosed — consequences.

The US and its NATO and Group of Seven wealthy democracies allies worry that the movement of Russian troops and weapons to the border region could be precursor to an invasion, and have vowed to inflict heavy sanctions on Russia’s economy if that happens. Moscow denies having any plans to attack Ukraine and accuses Kyiv of its own allegedly aggressive designs.