WASHINGTON (TIP): Russian defence minister Sergei Shoigu promised his US counterpart Chuck Hagel in a telephone call on Thursday that Moscow would not assault eastern Ukraine.

Hagel voiced concern about Russian military movements but Shoigu assured him that “the troops he has arrayed along the border are there to conduct exercises only and they have no intention of crossing the border into Ukraine and that they would take no aggressive action,” Pentagon spokesman Rear Admiral John Kirby told reporters.

Hagel also asked how long the military “exercise” would last but Shoigu “didn’t have a firm time frame for that,” Kirby said. Washington has watched a Russian buildup on Ukraine’s eastern border with growing concern after Moscow’s intervention in Crimea.