President Donald Trump said he was disappointed with Russia for launching missile strikes while efforts were underway to broker a peace agreement between Russian President Vladimir Putin and Ukrainian President Volodymyr Zelenskyy.

Speaking with reporters, Trump addressed a wide range of topics, including the Russia-Ukraine peace talks.

Putin first proposed the meeting in an apparent attempt to derail Western nations’ intentions to impose further sanctions if Moscow did not commit to a 30-day truce on a few weeks ago. In response, Ukrainian President Volodymyr Zelensky requested that the Russian leader meet with him in person in Istanbul.

Dmitry Peskov, Kremlin spokesperson, said that Moscow will send a team but did not indicate who would represent Russia. He also declined to confirm if Putin will attend the talks.

Reports indicate that U.S. officials have floated a potential ceasefire proposal that would include recognizing Russia’s control of Crimea—territory it annexed in 2014—and freezing current frontlines. However, Zelenskyy has made it clear that Crimea remains a non-negotiable red line.