The U.S. government is seeking to establish responsibility for the crimes of the Russian troops in Bucha and other areas, using all available tools, the U.S. Embassy in Ukraine reported.

"The images coming out of Bucha and other areas abandoned by Putin’s forces are horrific. The U.S. government is committed to pursuing accountability using every tool available. We can not stand quiet, the world needs to know what happened, and we all must act, " the Embassy said on Twitter Sunday.

At the same time, Romanian President Klaus Iohannis also stated the need to stop Russia's illegal aggression against Ukraine and that all those responsible should pay for what happened in Bucha and other Ukrainian cities.

"The Russian invasion of Ukraine has terrible, unspeakable consequences - the images of Bucha&other towns in Ukraine must be a reminder for the whole world that we must stop this illegal aggression and that all those found responsible must pay! The international justice should prevail! " Iohannis said on his Twitter account Sunday.