Ukrainian President Volodymyr Zelenskyy reiterated Friday that there must be more pressure on Russia to achieve a sustainable ceasefire. He added that Russian President Vladimir Putin has continued to act as an "aggressor" in the war, and hasn't halted any aerial attacks. "There is no silence still, only because Putin does not accept this proposal. Therefore, pressure is needed," he stressed. Ukraine and Russia agreed in principle Wednesday to a limited ceasefire after U.S. President Donald Trump spoke with the countries’ leaders this week, though it remained to be seen what possible targets would be off limits to attack. Visiting Czech President Petr Pavel echoed similar sentiments to Zelenskyy saying that "any ceasefire must be a step towards a sustainable peace". However, he emphasized that a possible ceasefire is more "within reach". AP Photo/Efrem Lukatsky