Ukraine agreed to launch peace talks with Russia on Sunday, even as battles raged in key cities and President Vladimir Putin raised the prospect of a nuclear escalation with the West. Delegations from each country are set to meet at the Ukrainian-Belarusian border, the office of Ukrainian President Volodymyr Zelensky said. There are no conditions to the planned talks at the border, according to the statement. Zelensky had previously refused an offer by the Kremlin to meet in Belarus proper, pointing to the fact that Russia had partially staged its invasion of Ukraine out of that country. The a…