The  EU has lined up sanctions against Russian officials over the poisoning of opposition leader Alexei Navalny and against Belarus leader Alexander Lukashenko over the crisis in his country.

Foreign ministers meeting in Luxembourg agreed in principle to sanctions proposals made last week by France and Germany, which said Russia was responsible for the poisoning of Navalny with the Soviet-developed nerve agent Novichok, three diplomatic sources told AFP.

On Belarus, the ministers said they were ready to sanction strongman leader Lukashenko, as the bloc seeks to step up pressure over his regime's crackdown on protesters.

The EU has already imposed travel bans and asset freezes on 40 Lukashenko allies for rigging an election in August that returned him to power and then orchestrating a crackdown on the mass protests that have rocked the country since the vote.

The bloc had held back from penalising Lukashenko, hoping to persuade him to open a dialogue with opposition forces to resolve the crisis.

But a fresh outbreak in Minsk on Sunday - police using water cannon and stun grenades on protesters and making hundreds of arrests - prompted ministers to give political approval to sanctioning the strongman leader.

In their formal conclusions on Belarus, the ministers said the list of sanctioned people and entities would be put "under constant review".

"The EU stands ready to take further restrictive measures, including against entities and high-ranking officials, including A. Lukashenko," the ministers said.

As he arrived for the meeting in Luxembourg, German Foreign Minister Heiko Maas had urged his counterparts to expand the sanctions list to include the strongman leader.

"The violence continues, perpetrated by the Lukashenko regime - there are still arrests of peaceful demonstrators, so we have to consider how to proceed," said Maas, whose country currently holds the EU's rotating presidency.

"I have suggested that we establish a new package of sanctions. And Lukashenko should be among the people who will then be sanctioned."

The EU rejected the results of the August 9 election and said it did not regard Lukashenko as the legitimate president.

The ministers' statement on Monday condemned police violence against protesters and demanded officials seek a peaceful end to the crisis through dialogue with the opposition, backing calls for new elections.

A protestor holds a placard depicting Belarusian President Alexander Lukashenko during a rally of solidarity with Belarusian protests on Independence Square in Kyiv, Ukraine on October 11. Photo: AFP

Novichok plot

Germany and France last week accused Moscow of responsibility for poisoning Navalny with the Soviet-developed Novichok nerve agent, saying "no credible explanation has been provided by Russia".

They said they would push for sanctions targeting "individuals deemed responsible for this crime and breach of international norms, based on their official function, as well as an entity involved in the Novichok programme".

After Monday's political green light, technical work will be started to prepare the sanctions, with one diplomat telling AFP they hoped it would move quickly.

The ministers on Monday extended the EU's chemical weapons sanctions framework, under which four Russians accused of involvement in the Novichok poisoning of an ex-double agent in England have already been listed.

Sanctions related to the Navalny case will be made under this framework, which has also been used against Syrian officials for carrying out chemical weapons attacks on their civil war foes.

The sanctions push came after UN chemical weapons watchdog OPCW confirmed Germany, France and Sweden's finding that the Russian opposition leader was poisoned by a nerve agent of the Soviet-developed Novichok group.

Monday's meeting will also take stock of EU-brokered talks between Serbia and Kosovo, as well as the conflict in Nagorno-Karabakh.