Kharkiv (Ukraine) (AFP) - Ukraine President Petro Poroshenko said Tuesday he has "no doubt" the US will provide weapons for the fight against pro-Russian separatists, after Washington signaled it may be ready for the risky move.

"I have no doubt that a decision on the possible delivery of arms to Ukraine will be approved both by the United States and by our other partners," Poroshenko said.

"We have to have the means to defend ourselves," he told journalists in the eastern city of Kharkiv after at least 19 civilians and five government troops were killed in fighting with pro-Russian rebels over the previous 24 hours.

US Secretary of State John Kerry will jet into Ukraine on Thursday in a show of support for the country's pro-Western leadership as hopes grow in Kiev that long-standing demands for the US to supply arms could be met.

President Barack Obama's administration had previously ruled out sending weapons to Ukraine's government but the failure of economic sanctions to force Moscow to halt alleged military support for the separatists has prompted a second look at the option.

While Kerry is not expected to make any announcements during his trip, a Ukrainian diplomatic source said Kiev was hoping to get more "clarity" on its request during the visit and an upcoming meeting between Poroshenko and US Vice President Joe Biden in Munich.

Washington -- fearful of getting into a proxy war with Russia -- has so far provided non-lethal assistance to Ukraine, including flak jackets, medical supplies, radios and night-vision goggles.

But a senior US official told AFP Monday that "what's being discussed is perhaps we should begin providing defensive weapons" to Ukraine.

- Death toll soars -

As the United States weighed up its options, intense fighting remains focused around the battleground town of Debaltseve, a strategic railway hub between the rebel strongholds Donetsk and Lugansk where separatists are fighting to encircle Ukrainian forces.

Story continues

Fighting has surged in recent weeks after separatists tore up a tenuous ceasefire deal and pushed into government-held territory.

Elena Gura was having breakfast with her 16-year-old daughter in Donetsk when a shell crashed through her kitchen ceiling.

"We escaped with 300 hrvyna (around 15 euros, $18) and some identity papers," she told AFP after miraculously escaping her destroyed house, her hair and clothes still wet from the firefighters' hose.

The United Nations said Tuesday the civilian death toll has risen by 224 in the past three weeks and that the total of those killed in the conflict since April now stands at over 5,358 people.

"Any further escalation will prove catastrophic for the 5.2 million people living in the midst of conflict in eastern Ukraine," warned UN High Commissioner for Human Rights Zeid Ra'ad Al Hussein

Hopes of defusing the conflict look more distant than ever after the latest attempt at truce talks collapsed in acrimony in the Belarussian capital Minsk over the weekend.

The rebels say they are willing to stop fighting only if Kiev agrees to redraw the demarcation line agreed in a September ceasefire deal to include gains they have made since in recent days.

- Rebel call-up -

Life for civilians trapped in the crossfire continues to deteriorate rapidly.

"The situation is getting worse by the day," the head of the International Committee of the Red Cross in Ukraine, Michel Masson, said in a statement.

"People are hiding in basements for days on end and those who dare to venture out to collect basic aid risk being wounded or killed."

Ukraine and its Western allies accuse Moscow of sending thousands of regular army troops and weapons to support the rebels.

Moscow has repeatedly denied the allegations but the rebels appear to be equipped with the heavy weaponry of a regular army.

As rebels continued to push their offensive, their leaders have announced a mass mobilisation aimed at boosting fighter numbers to 100,000.

The voluntary call-up -- which has been met with scepticism by some in rebel-held territory -- is set to start on Monday, insurgent leader Alexander Zakharchenko said.

Kiev authorities announced at the end of January that they were also calling up 50,000 troops in the face of the latest separatist push.