"In Kyiv on joint visit with Polish FM #Waszczykowski to show Ukraine we are 100% behind them against Russian aggression," he tweeted.

On March 1, Foreign Ministers of Britain and Poland Boris Johnson and Witold Waszczykowski pay a joint visit to Ukraine.

The agenda will address the issues of peaceful settlement of the situation in Donbas, the state of human rights in the temporarily occupied Crimea, a long reform process, the EU-Ukraine relations, as well as the prospects of the Normandy Four negotiation process.

Read alsoStanding side-by-side: British Ambassador vows support for Ukraine regardless of BrexitAs reported, Boris Johnson has already had breakfast at Veterano pizzeria, which was established by ATO veterans.

At the same time, a journalist Christopher Miller cited the pizzeria owner, the ATO veteran who he spoke to Boris Johnson on Ukraine war, as saying that the British foreign minister "knows practically nothing about what's going on (or gave that impression)."