President Dmitry Medvedev launched a Kremlin drive to bring Ukraine into its fold on Tuesday as he waded into the country’s presidential elections with a call for a new leader to break with the “anti-Russian” policies of the incumbent and to co-operate with Moscow.

In an open letter to Viktor Yushchenko, neighbouring Ukraine’s pro-western president, the Russian leader refused to renew diplomatic ties by saying he was postponing the dispatch of a new ambassador to Kiev until there was a change in relations.