Commenting on his trip, Sanader said on Thursday that he and his British host, Prime Minister Tony Blair would discuss bilateral topics and issues relating to south-eastern Europe.
"This will be an occasion to upgrade our relations," Sanader said in Kiev where he was attending an international conference of the Yalta European Strategy (YES) network.
Sanader is due to fly to London on 18 July.
On 21 July he will visit Belgrade.
"Normalisation of relations between Croatia and Serbia can be a pillar of political stability in this part of Europe," Sanader said announcing his trip to Serbia.