By Maria Tsvetkova, Dmitry Antonov and Andrea Shalal
KYIV/MOSCOW/WASHINGTON (Reuters) - Kyiv appeared to blame Russia for a cyber attack on Tuesday as U.S. President Joe Biden warned that more than 150,000 Russian troops were still amassed near Ukraine's borders after Moscow's announcement of a partial pullback was met with scepticism.
World powers are engaged in one of the deepest crises in East-West relations for decades, jostling over post-Cold War influence and energy supplies as Moscow wants to stop the former Soviet neighbour ever joining the NATO military alliance.
Western nations have suggested arms control and confidence-building steps to defuse the standoff, which has prompted them to urge their citizens to leave Ukraine because an attack could come at any time. Russia denies it has any plans to invade.