And on tuesday, the u.s. secretary of state antony blinken said the u.s. could not confirm the use of chemical weapons in ukraine, particularly in the port city of mariupol. but he noted there is credible information that russian forces may use a variety of riot control agents. here s what the ukrainian president had to say about a potential chemical weapons attack. translator: given the repeated threats of russian propagandists use chemical weapons against the defenders of mariupol and its repeated use by the russian army, such as phosphorus munitions in ukraine, the world must respond now. react preventively because after the use of weapons of mass destruction, any response will not change anything, and it will only look like a humiliation for the democratic world. the russian president vladimir putin says peace talks are at impassione, and this ware