"David Cameron is to go to Moscow in September in what will be the first visit by a British prime minister to Russia since the murder of former KGB agent Alexander Litvinenko in London.
"The announcement by the Russian embassy in London is seen as a sign that diplomatic relations damaged by the high-profile killing are improving.
"Alexander Sternik, charge d'affaires at the embassy, said Cameron would travel to Moscow in "early September".
""We hope it will be a very significant step forward in improving our relationship," he added."