Haggard but relieved after days of fierce fighting with pro-Russian rebels, Ukrainian soldiers on Wednesday retreated on foot and by truck from the battleground town of Debaltseve.

Covered in the grime and soot of battle the government troops arrived at the nearest Kiev-held town of Artemivsk -- some 35 kilometers away (22 miles) -- exhausted and hungry.

The Lebanese state reportedly rejected a Russian offer to deliver to the Lebanese Army TOS-1 heavy flamethrower systems.

According to al-Akhbar newspaper published on Wednesday, Russian authorities expressed readiness, through direct and indirect channels, to deliver the multiple rocket launcher to Lebanon from a $1 billion Saudi donation.

Ukraine's President Petro Poroshenko on Wednesday called for a U.N.-mandated peacekeeping force to monitor a tattered ceasefire deal in east Ukraine.

"We see the best format would be a police mission from the European Union. We are sure this would be the most effective and best guarantee for security," Poroshenko said at the start of a meeting with security chiefs. 

Canada announced Tuesday new sanctions against Moscow and its sympathizers, including the state oil giant Rosneft, as pro-Russian separatists defied a ceasefire and stormed a flashpoint town in eastern Ukraine.

Two months after sanctions took aim at Russian interests in its vital oil and gas sectors, Canada targeted a flagship of the Russian economy in Rosneft.

The leaders of Russia, Germany and Ukraine have agreed on "concrete measures" to allow OSCE observers to monitor the shaky ceasefire in Ukraine, Berlin announced on Tuesday.

The measures were agreed during a late Monday phone call between German Chancellor Angela Merkel and her Russian and Ukrainian counterparts, Vladimir Putin and Petro Poroshenko, the government spokesman said in a statement, without providing details of the agreed steps.

Street-to-street fighting broke out for the first time inside a flashpoint town in east Ukraine on Tuesday, officials and pro-Russian rebels said, dealing a harsh blow to a fragile ceasefire just three days old.

The combat in Debaltseve, a strategic railway hub located between the separatist-held cities of Donetsk and Lugansk, was described as "intense".

Russian Ambassador to Lebanon Alexander Zasypkin praised dialogue among the Lebanese parties, considering it a necessity to combat the challenges and risks that the country is passing through.

“Foreign countries support the dialogue, in particular because it is touching on local and regional issues, in the first place the battle against terrorism and extremism,” Zasypkin said in an interview with An Nahar newspaper on Tuesday.

Hundreds of Hungarians took to the streets of Budapest on Monday to protest against Vladimir Putin, a day ahead of the Russian leader's visit to Budapest. 

According to an Agence France-Presse photographer, around 2,000 people marched between the capital's two main train depots, the Eastern and Western stations. 

The European Union included two Russian deputy defense ministers in its latest Ukraine sanctions list Monday, hitting them with travel bans and asset freezes for their role in the conflict.

The EU's Official Journal named Deputy Defense Minister Anatoly Antonov and first Deputy Minister of Defense Arkady Bakhin for supporting Russian troop deployments in Ukraine.

The controversial sale of two high-tech warships to Russia is "not on the agenda", France's defense minister said on Monday, despite the ceasefire agreed in Ukraine last week.

"It's not on the agenda," Jean-Yves Le Drian told French radio.