Boris Johnson has warned the UN secretary general that Vladimir Putin will attempt to "manipulate" his visit to Moscow this week.

       In a call on Sunday afternoon, Mr Johnson told Antonio Guterres to be "careful" because Putin will seek to use his visit as a propaganda tool. The Prime Minister said the Russian president's campaign in Ukraine was "nauseating".

       Downing Street sources suggested Mr Johnson was concerned about the visit, during which Mr Guterres will have a working lunch with Sergei Lavrov, the Russian foreign minister, and meet Putin in Moscow.

       A spokesman added that he had condemned the "blatant aggression" of Russia in Ukraine and "shared concerns on attacks in areas besieged by Russian forces, such as Mariupol and Kherson, and the need to secure a ceasefire, facilitate humanitarian efforts and allow civilians to leave".

       During Liz Truss's visit to Moscow in February, Mr Lavrov likened their discussions to "the conversation with a deaf person… who is here, but does not hear". He then walked away from a press conference, leaving the Foreign Secretary standing alone at the lectern.

       Earlier this month, Karl Nehammer, the Austrian chancellor, held a "not friendly" meeting with Putin at his official residence outside Moscow.

       He was criticised for attempting to negotiate with the Russian president over Ukraine, which the Czech foreign minister said was "naive" and one EU diplomat called "f------ pointless".

       On Friday, a UN spokesman said Mr Guterres "hopes to talk about what can be done to bring peace to Ukraine urgently" before visiting Volodymyr Zelensky, the Ukrainian president, and Ukraine's foreign minister on his way home.

       He will also meet UN staff providing support on the ground for refugees who have been forced to leave their homes by bombing and fighting.

       Putin is rarely seen other than in carefully-managed photographs from inside the Kremlin, amid reports that he has experienced health problems.

       Russian government agencies have repeatedly released video and photo "evidence" from the ground in the Ukrainian conflict that has been doctored to support false Kremlin narratives about the war.

       A Number 10 spokesman said: "The Prime Minister made clear the importance of global solidarity with Ukraine, with the UK continuing to work closely with international partners to support Ukraine to defend itself."