Pope Francis called on the relatives and close friends of victims of the Nice truck attack to come together and resist hatred and violence during a ceremony at the Vatican on Saturday.

"If the temptation is great to withdraw into oneself, to respond to hatred with hatred and to violence with violence, then an authentic conversation with the heart is needed," Pope Francis told the 300 relatives of the victims.

The ceremony was attended by about 1,000 people, including members of Nice's Jewish community as well as a local Muslim imam.

"It cheers me to see that, among you, inter-religious relations are very strong, and this cannot but help contribute to alleviating the wounds of these dramatic events," said Pope Francis.

Former Nice Mayor Christian Estrosi gave the pontiff a basket of 86 flowers to symbolize the 86 people who died in the July 14 attack by an extremist who plowed a truck into a crowd celebrating France's national day.

The self-styled "Islamic State" (IS) group claimed responsibility for the attack. Less than two weeks later, militants who pledged allegiance to IS murdered Father Jacques Hamel, an elderly French priest, in his church.

"I pray to the God of mercy also for those who were wounded, in some cases atrociously mutilated, in flesh and in spirit, and I don't forget all those who for that reason weren't able to come here or are still in hospital," the pontiff said.

Still, Pope Francis' message on Saturday was one of understanding, calling for "the establishment of a sincere and fraternal dialogue among everyone," which he said was "an urgent priority for all those in authority, be they political or religious."

On Tuesday, Francis held peace talks with religious leaders on World Prayer Day when he denounced religious extremism.

"There is no God of war," emphasized Francis during the meeting.

rs/jm (AP, dpa, Reuters)