European leaders will take part in the rally in an extraordinary act of solidarity with France, after it was rocked by terrorist attacks targeting satirical paper Charlie Hebdo and a Kosher store in Paris.

The Paris rally is one of scores due to be held around France on Sunday to pay respects to the victims of the attacks and call for unity.

Along with French President Francois Holland, the event in Paris is due to be attended by leaders of numerous European countries.

British Prime Minister David Cameron, who was among the first to confirm attendance, said that the event would celebrate the "values of Charlie Hebdo".

Cerar's office added that by travelling to Paris, Cerar will be unable to attend a meeting of WWII veterans in Dražgoše, which is the site of one of the biggest battles of the second world war on Slovenian territory.

Slovenian officials have strongly condemned the attacks in Paris, labelling them as attacks on the values of modern civilisation. The country has also seen broad expressions of support for the French people in recent days, and rallies have also been held in support of freedom of expression.