The EU will give Ukraine 600 million euros ($640 million) to bolster government finances, European Commission head Jean-Claude Juncker said Friday, as Kiev faces an upsurge in fighting with pro-Russian rebels.

Juncker, speaking after talks with Ukraine Prime Minister Volodymyr Groysman, said the country had pressed ahead with reforms despite difficult conditions and the EU should now make good its aid pledges.

"This will be done in the next coming weeks because I think that after having watched the reform effort of Ukraine, Ukrainians have the right to see something in return," he told reporters.

"We are supporting Ukraine, not only in its conflict with Russia, but more generally ... We have a strategic partnership with Ukraine and our future relations will develop along these lines."

Groysman said it was very important to send a strong signal to citizens that the tie-up with the EU was "a positive result and would improve their lives."

Juncker added that he expected visa liberalisation for citizens of Ukraine, long sought by Kiev, would be in place by the middle of the year.

In recent weeks, the government has faced a very sharp spike in fighting with rebels in the east amid speculation Russia was stoking the conflict to test how new US President Donald Trump would react after he said he favoured improving links with Moscow.

Pro-European Union protests in early 2014 ousted pro-Russian president Viktor Yanukovych and his successor Petro Poroshenko turned his back on Moscow in favour of a future with the EU.

The two sides signed an association agreement, and a free trade deal, to bolster Ukraine's struggling economy, with Brussels offering 3.4 billion euros in loans to help Kiev balance the public finances.

The EU has so far handed over 2.2 billion euros, with disbursements tied to progress on political and economic reforms meant to end corruption and put Ukraine, a Soviet-era satellite, on a par with European norms.