Russian Defence Minister Sergei Shoigu said Tuesday that Moscow's forces were "progressing with success" near the eastern Ukrainian towns of Bakhmut and Vugledar, cautioning against Western arms supplies to Kyiv.

"The US and its allies are trying to drag out the conflict as long as possible. To do this, they have begun supplying heavy offensive weapons (to Kyiv) and openly calling on Ukraine to seize our territories," Shoigu told a defence meeting.

"Such steps draw NATO countries into the conflict and could see it escalate unpredictably," Shoigu said.