BBC News with Julie Candler

The opposition Nationalist candidate in Serbia, Tomislav Nikolic, has unexpectedly won the Serbian presidential election. Nick Thorpe reports from Budapest.

Tomislav Nikolic has claimed victory, and in his first remarks, said 'Serbia will not stray from its European path' – that is clearly an attempt to

soothe

observers in Western Europe and the United States who see him as an unknown quantity. Boris Tadic has now admitted defeat. As president, Boris Tadic has made major progress towards EU membership for Serbia – almost expected to win reelection by a small but comfortable margin. Mr Nikolic is a former Nationalist who had

steered

his progressive party towards the political center.

President Obama has warned of 'hard days ahead' for Afghanistan at the start of a Nato summit in Chicago to discuss future strategy for the country. Addressing a news conference with the Afghan President Hamid Karzai, President Obama said Nato was confidence it was going in the right direction. President Kaizai said Afghanistan came to the summit as a sovereign country, and was committed to the withdrawal of its Nato partners in 2014, but was also conscious of the challenges that would bring.

"Afghanistan is fully aware of the task here and of what Afghanistan needs to do to reach the objectives that we all have a stable, peaceful and

self-reliant

Afghanistan."