Ukraine's president said he hopes the U.S. applies "maximum additional sanctions" on Russia if it refuses to accept a 30-day ceasefire, describing the Russian leader's "bravado" as a stalling tactic.

Russia is trying to undermine peace talks and should be slammed with tough new sanctions, Ukrainian President Volodymyr Zelenskyy said Thursday ahead of negotiations between the U.S. and Moscow. Ukraine agreed to a Trump administration proposal for a 30-day pause in fighting earlier this week after high-level talks with a U.