US president Donald Trump’s special envoy to Ukraine and Russia has arrived in Kyiv, a senior Ukrainian official said, as anticipation grew over possible changes in the Trump administration’s policies ...

The United States, Trump stressed, would not pay for them as he heaped fresh criticism on Russian President Vladimir Putin.

Ukraine’s security agency said on Sunday it tracked down and killed Russian agents suspected of shooting one of its senior officers in the Ukrainian capital. The security service of Ukraine, or SBU, ...

With the use of autonomous recording units, or ARUs, scientists can listen to bird frequencies to understand their behaviors.