Ukraine dispatched top envoys to Washington and Brussels on Wednesday to secure help in the face of a surge in clashes with pro-Russian insurgents that killed eight more civilians and troops.

A one-month truce in Ukraine is teetering on the verge of collapse just weeks before a general election meant to reunify the country after half a year of warfare in the east has killed nearly 3,400 people.

The number of civilians dead from shelling and mortar attacks grew to 19 since the weekend when Donetsk authorities reported three additional deaths in the main rebel-held city overnight.

An AFP team also saw two bodies of victims of rocket fire that hit a supermarket and some residential buildings in a northeastern section of the half-deserted city that was once home to nearly a million people.

National Security and Defence Council spokesman Andriy Lysenko said fighters killed three and wounded 12 Ukrainian soldiers in renewed attacks.

Ukrainian authorities have reported the death of more than 100 troops and civilians since separatist leaders and Kiev signed a September 5 truce that was backed by both Moscow and EU states.

But the UN human rights office said the post-ceasefire toll up to Monday may be as high as 331.

"Tragically, the political agreement is not being observed," Ukrainian Defence Minister Valeriy Geletey said.

The crisis has torn at East-West relations and seen Russian President Vladimir Putin thrown into diplomatic isolation for his alleged bid to break up his neighbour in retaliation for the ouster of a pro-Kremlin president in February.

Rebel leaders now intend to keep the October 26 parliamentary polls from being staged across swathes of the Russian-speaking rustbelt that are home to nearly five million people.

They instead plan their own votes in early November that would set up parliaments and administrations allied to Moscow and intended to ensure complete self-rule.

Ukrainian President Petro Poroshenko has urged Russia to convince the fighters to resume political negotiations that could grant them broader rights within a single state.

But the Kremlin denies having any hand in the conflict and accuses the West of trying to wrest the ex-Soviet country out of Russia's sphere of influence.

- IMF and NATO -

Ukraine's top policymakers travelled to NATO and EU headquarters in Brussels as well as the head International Monetary Fund office in Washington to win further diplomatic and economic backing from Kiev's new partners.

Foreign Minister Pavlo Klimkin shook hands for the first time with new NATO Secretary General Jens Stoltenberg -- a liberal former Norwegian premier who last week said the bloc was ready to seek constructive ties with Moscow.

"The NATO secretary general has changed, but the priority importance of Ukraine remains the same," Klimkin tweeted after the meeting.

He said the country would seek European Commission funding to help eastern residents survive the winter with limited access to essential supplies.

Ukrainian Central Bank chief Valeria Gontareva was meanwhile meeting with IMF boss Christine Lagarde in the hope of speeding up the delivery of a $17.1-billion (13.5-billion-euro) loan and even expanding the amount.

Prime Minister Arseniy Yatsenyuk told his cabinet that Gontareva would ask the IMF "to modify its programme taking current realities into account".

The two-year IMF arrangement is part of a global $27-billion package approved in April to help the new leaders avert a looming bankruptcy and pull Ukraine out of its third recession in six years.

But the economic slide has only accelerated and is now expected to see the economy shrink by up to nine percent this year.

The IMF itself warned last month that Ukraine may need an additional $19 billion in short-term assistance should the eastern campaign stretch through the end of next year.