China is in, after other world powers condemned Moscow for sending troops into the country.

Hundreds of Russian soldiers have surrounded a military base in Crimea, preventing Ukrainian soldiers from going in or out. The convoy blockading the site, near the Crimean capital Simferopol, includes at least 17 military vehicles. Russian troops are also reported to have taken control of a ferry terminal in the city of Kerch on the eastern tip of Crimea, which has a majority Russian-speaking population.

Ukraine’s defence ministry said two Russian fighter jets violated the country’s air space in the Black Sea on Sunday night and that it had scrambled an interceptor aircraft to prevent the “provocative actions”. And reports claimed pro-Russian protesters had occupied a floor of the regional government building in Donetsk. The 11-storey building has been flying the Russian flag for the last three days.

Russian foreign minister Sergei Lavrov discussed Ukraine by telephone with his Chinese counterpart, Wang Yi, on Monday, and claimed they had “broadly coinciding points of view” on the situation there, according to a ministry statement. Speaking at the UN Human Rights Council in Geneva later, Mr Lavrov said Russian troops were necessary in Ukraine “until the normalisation of the political situation” and dismissed threats of sanctions and boycotts.

US Secretary of State John Kerry will visit Kiev on Tuesday to show “strong support for Ukrainian sovereignty”. Meanwhile, Ukraine launched a treason case against its new navy chief after he switched allegiance to the pro-Russian Crimea region. Russian President Vladimir Putin on Saturday won parliament’s authorisation to use force in Ukraine.

– Scott Randell (@DefinedByMvsic)