Moscow, 11 April 2022 (dpa/MIA) - Austrian Chancellor Karl Nehammer reported coming away from a meeting with Russian President Vladimir Putin with "no optimistic impression" after the two had talks at Putin's residence outside Moscow on Monday. Nehammer also told journalists in Moscow that the Russian military was preparing a fresh offensive in eastern Ukraine, adding that "this battle will be fought with vehemence," and urging civilians in the contested areas to use humanitarian corridors to escape the fighting. Nehammer was the first EU leader to meet Putin in person since the outbreak of war over six weeks ago, though the meeting at Putin's residence lasted no more than an hour, suggesting that no progress had been made. The chancellor's most important message to the Russian president had been that the war must end as in war there were only losers on both sides, the chancellery said, describing the conversation as "very direct, open and tough." Nehammer said he had addressed Russian war crimes in Bucha, among other places, and stressed that those responsible for the killing of civilians must be held accountable. The Austrian chancellor rejected criticism for his decision to meet with the Russian leader in person. "Personal confrontation is needed," he stressed, adding that both Nehammer's fellow EU leaders and Ukrainian President Volodymyr Zelensky had been aware of and supported the meeting. In Ukraine itself, fighting continued across the country on Monday and culminated with the Donetsk separatist leader Denis Pushilin claiming that the fiercely contested port of the embattled south-eastern Ukrainian city of Mariupol had fallen to the Russians, in remarks cited by Russian news agencies RIA and Interfax. The separatists have been fighting for weeks with the support of the Russian army to capture Mariupol, which is strategically important due to its location on the Sea of Azov. While Ukrainian officials did not confirm or deny the claim, they accused Russia of seizing a ship at the port and arresting its crew. The Ukrainian parliament's human rights commissioner Lyudmyla Denisova wrote on Telegram that Russian troops had fired on the Liberian-flagged ship. The Ukrainian army's General Staff issued a warning that Russian troops stationed in the breakaway Transnistria region of Moldova could be used to launch an attack on Ukraine from the west. Transnistria, which lies on Ukraine's western border, is legally part of Moldova, but has been controlled by Russia since 1990. Should Russian troops from Transnistria and paramilitary groups loyal to Moscow from the region intervene in the war, there is a potential threat of encirclement to Ukrainian forces in the south of the country, especially around the Odessa region. Meanwhile Kiev reported a further concentration of Russian troops in eastern Ukraine, including troops redeployed from Siberia and the Russian Far East. "It is likely that the occupiers will try to renew their offensive in the next few days," the Ukrainian General Staff said. Ukrainian President Volodymyr Zelensky continued to call for more support from the international community on Monday. He asked South Korea to alter its policy and to supply him with weapons during a video address to the National Assembly in Seoul. "There can be no hope that Russia will just stop itself," he said in the speech, which was shown on television in both Ukraine and South Korea. "We need air defence systems, we need aircraft, tanks, other armoured technology, artillery systems and ammunition," he said, appealing to both South Korea and the international community.