Syrian President Bashar al-Assad said Europe is a "direct cause" of Syrians fleeing their homeland and must stop "giving cover to terrorists" before people return.
In an interview to AFP, Assad called on European governments "which have been a direct cause for the emigration of these people ... to help in making Syrians return to their country".
He also said he supports negotiations to end his country's conflict, but insisted he would not stop fighting "terrorism".
He said: "We have fully believed in negotiations ... however, if we negotiate, it does not mean that we stop fighting terrorism. The two tracks are inevitable in Syria.
Assad said he rejected the United Nations recent accusations that his regime is guilty of war crimes, calling the claims "politicised".
The UN lambasted his government for "exterminating" prisoners in its jails and detention centres, but when speaking to AFP, Assad said that the accusations "serve a political agenda ... and do not provide any evidence."
Russia must change for Syria ceasefire - Britain
Earlier, Britain's foreign minister said a deal to end fighting in Syria requires a "change in behaviour" from the regime of Bashar al-Assad and his ally Russia to succeed.
At crisis talks in Munich, Germany, over Syria's civil war, world powers agreed to implement a "nationwide cessation of hostilities" beginning in a week's time.
"If implemented fully and properly ... this will be an important step towards relieving the killing and suffering in Syria," British Foreign Secretary Philip Hammond said in a statement.
"But it will only succeed if there is a major change of behaviour by the Syrian regime and its supporters."
Mr Hammond cautioned that Assad ally Russia "claims to be attacking terrorist groups and yet consistently bombs non-extremist groups including civilians.
"If this agreement is to work, this bombing will have to stop: no cessation of hostilities will last if moderate opposition groups continue to be targeted," he said.
Foreign ministers talked late into the night in Munich to try to revive the peace process, which has so far failed to halt a five-year war that has killed more than 260,000 people and displaced millions.
Writing on Twitter, Britain's special representative for Syria Gareth Bayley said the agreement had been "hard won".
At a news conference, US Secretary of State John Kerry acknowledged the Munich meeting produced commitments on paper only.
"What we need to see in the next few days are actions on the ground, in the field," he said, adding that "without a political transition, it is not possible to achieve peace."
Russian Foreign Minister Sergei Lavrov told the news conference that Russia would not stop air attacks in Syria, saying the cessation of hostilities did not apply to the self-styled Islamic State group and al Nusrah, which is affiliated with al Qaeda.
Islamic State militants control large parts of Syria and Iraq.
"Our airspace forces will continue working against these organisations," he said.
The United States and European allies say few Russian strikes have targeted those groups, with the vast majority hitting Western-backed opposition groups seeking to topple the government of President Bashar al-Assad government.
Meanwhile, a special UN task force has demanded immediate aid access in Syria. Countries backing the US and Russian-led plan for a cessation of hostilities in Syria have requested access to besieged towns and expect approval from the warring parties without delay, the group's chairman Jan Egeland said today.
The Task Force on Humanitarian Access in Syria met at the UN in Geneva less than 24 hours after it was set up by major and regional powers meeting in Munich.
"We have already submitted requests for access to the parties surrounding besieged areas," Mr Egeland said in a statement.
"We expect to get such access without delay," he added.
