MOSCOW • Ukraine has accused pro-Russian militants of intensifying attacks on government troops overnight to win ground, a sign that the recent surge in fighting is worsening, as the Kremlin said Russian President Vladimir Putin discussed the spike in violence with his security council.

Tensions in the 16-month conflict rose this week as Ukraine's army reported renewed assaults on a village in the Donetsk region, an accusation the separatists deny.

That prompted Kiev to redeploy heavy artillery that was removed under a February peace accord signed in Minsk, Belarus.

The rebels, who control large swathes of the former Soviet republic's eastern-most regions, are trying to advance again towards the village, located near the port of Mariupol, military spokesman Andriy Lysenko said.

The insurgents "shamelessly violate the truce accords", Mr Lysenko said yesterday by phone.

He said the rebels were using arms that included mobile rocket systems banned under the ceasefire brokered by Germany and France in a flurry of diplomacy.

One soldier died in the past day, the military reported.

Rebel leaders have denied firing on Ukrainian positions.

The conflict, which the United Nations estimates has killed more than 6,700 people, has threatened to boil over several times since the peace pact was signed as Ukraine, Russia and the separatists jostle over implementing its terms.

German and French officials have discussed the recent unrest with Ukraine's government, while the United States tightened sanctions against Russia last week.

Mr Putin denies his nation is stoking the conflict.

The Interfax news agency, citing the Kremlin, yesterday said the Russian leader recently discussed the uptick in violence and ways to counter the Islamic State in Iraq and Syria with his security council.

This military escalation comes as Ukrainian Finance Minister Natalie Jaresko visits creditors in California to try and reach an agreement to restructure US$19 billion (S$27 billion) of foreign debt.

The government is in an economic bind with GDP plunging more than 16 per cent and the hryvnia this year's second-worst performing currency globally against the US dollar.

Meanwhile, intensified military exercises by Russia and Nato are fuelling tensions in Europe that have already been heightened by the conflict in Ukraine, according to a report by the London-based research group, European Leadership Network, yesterday.

In its defence, Nato said its exercises have been staged as a response to "growing Russian aggression".

REUTERS, BLOOMBERG, AGENCE FRANCE-PRESSE