U.S. special envoy Keith Kellogg met Belarusian President Alexander Lukashenko in Minsk, the highest-profile visit of a U.S. official to the authoritarian state in years.

Sergei Tikhanovsky, the husband of Belarus' opposition leader, has called on US President Donald Trump to "just say the word" and ask for all political prisoners in Belarus to be released.

Siarhei Tsikhanouski, a leading Belarus opposition figure, was freed on Saturday after more than five years in prison, in the most significant move so far by President Alexander Lukashenko to try to ease his isolation from the West.