The International Monetary Fund and conflict-torn Ukraine have reached a preliminary deal on a new financial rescue plan worth $17.5 billion that could be a "turning point" for Kiev, IMF chief Christine Lagarde said Thursday.

In total, Ukraine will receive $40 billion (35 billion euros) in assistance over four years coupled with bilateral loans from other sources, Lagarde said, helping to stabilize Kiev's finances after 10 months of conflict in the east.

Nine people were killed and 35 more wounded in fresh fighting in eastern Ukraine as marathon peace talks dragged on in Minsk, officials said on Thursday.

"As a result of shelling and clashes two Ukrainian soldiers were killed, 21 more were wounded," Vladyslav Seleznyov, spokesman for Ukraine's General Staff, told reporters.

A new roadmap aimed at ending a 10-month war between Ukraine and pro-Moscow rebels was agreed in Belarus Thursday, but skepticism remained as leaders warned much needed to be done before peace was achieved.

After a marathon summit in the Belarussian capital Minsk, Russian President Vladimir Putin said he, Germany Chancellor Angela Merkel, French President Francois Hollande and Ukrainian President Petro Poroshenko had reached a ceasefire deal.

One person was killed in the shelling of a hospital in the Ukraine separatist stronghold Donetsk on Wednesday at the same time as a peace summit was held in Minsk, authorities said.

"A shell hit hospital number 20, setting it on fire," separatist spokeswoman Yuliana Bedilo told Agence France-Presse, adding that a pedestrian had been killed outside the hospital.

The leaders of Ukraine, Russia, Germany and France on Wednesday began a crunch peace summit in Minsk aimed at ending 10 months of fighting in Ukraine where violence claimed dozens more lives. 

A grave-looking Ukrainian President Petro Poroshenko shook hands briefly with Russian leader Vladimir Putin as the two arch-foes came face-to-face for the first time since October to try to thrash out a peace plan.   

Russia's alleged tactics in the Ukraine conflict including covert military action and social media campaigns could inspire other nations such as China and Iran, a top defense think-tank warned Wednesday.

Most armies around the world are ill-prepared to tackle this new type of "hybrid warfare", the International Institute for Strategic Studies (IISS) said in its annual Military Balance report.

Croatian nationals, believed to be mostly veterans of the country's 1990s war, joined Ukraine's army to fight against pro-Russian rebels, Foreign Minister Vesna Pusic said Wednesday without giving any numbers.

"As far as I know there are (Croatian fighters) who joined the Ukrainian army," Pusic told reporters and added that the country's intelligence services were "following the issue."

EU foreign affairs head Federica Mogherini told AFP on Wednesday that a high-stakes Ukraine peace summit in Minsk would be a turning point in the conflict.

Mogherini also urged Moscow to take the chance to become a "responsible actor" and help end the 10-month war between Kiev and pro-Russian separatists.

U.S. President Barack Obama called his Russian counterpart Vladimir Putin to discuss escalating violence in eastern Ukraine and "Russia's ongoing support for the separatists there," the White House said Tuesday.

During the call Obama reiterated America's support for Ukraine's "sovereignty and territorial integrity," National Security Council officials said.

Intense fighting in Ukraine, including a devastating rocket strike on Kiev's military headquarters in the east, killed at least 37 people on Tuesday on the eve of a four-way peace summit.

As diplomats scrambled to finalize a deal to end the 10-month war, pro-Russia rebels sought to encircle railway hub Debaltseve and Ukrainian forces launched a counter-offensive around the strategic port of Mariupol.