The withdrawal comes the day after Vladimir Putin said four regions in Russian-occupied Ukraine were now part of Russia, having earlier threatened retaliation if his country was attacked. One regional governor has called for nuclear weapons to be used in response. News reporter Russian troops have pulled out of the city of Lyman in eastern Ukraine due to the risk they were being encircled by Ukrainian forces, the Kremlin has said. Lyman is in Donetsk - one of the Ukrainian regions that was annexed by Russian President Vladimir Putin in a ceremony in Moscow on Friday. And Mr Putin has previously threatened retaliation if Russia is attacked. Earlier, a spokesperson for Ukraine's eastern forces said Ukrainian forces had entered Lyman after encircling thousands of Russian soldiers and trapping them there. According to Ukraine's President Volodymyr Zelenskyy, fighting is still going on in the city. Russia's retreat has prompted Ramzan Kadyrov, head of Russia's Chechnya region and an ally of