Intense talks in Minsk continued on past dawn Thursday as the leaders of Russia, Ukraine, France and Germany sought to end 10 months of fighting in Ukraine.
The urgency felt by all sides appeared to be underlined by the extraordinary length and discomfort of the talks, and the continuing toll.
More than 5,300 people have died since April in the fighting between Ukrainian forces and Russia-backed separatists in two eastern provinces and the bloodshed rose sharply in recent weeks. And despite the ongoing talks, both rebels and government troops reported fighting across eastern Ukraine that continued overnight into Thursday.
Officials have remained tight-lipped. In the morning, the leaders briefly left the session hall but later came back to continue negotiations.
There were conflicting indications of progress or the lack thereof.
The Ukrainian Embassy in Kiev said a deal under preparation envisages a cease-fire starting from Saturday and the creation of a buffer zone, but gave no further details, according to The Associated Press.
"Unfortunately there's no good news yet," Ukrainian President Petro Poroshenko told AFP news agency.
"There are conditions that I consider unacceptable," he said, declining to elaborate. "The (negotiations) process is ongoing," he said during the brief break.
Late Wednesday, Russian Foreign Minister Sergey Lavrov signaled some progress, and said the most important goal of the talks would be to implement a cease-fire, but warned that Ukraine only could fully re-establish its control over the border with Russia if it offers a degree of autonomy to the east and lifts its economic blockade.
"To give away the Russian part of the border also would be to cut them (the rebels) off even from humanitarian help and allow them to be surrounded," Lavrov said.
Earlier on Wednesday, French Foreign Minister Laurent Fabius said that "quite a number of problems remain" in negotiations, including the future of eastern Ukraine, guarantees about the Ukraine-Russia border, and the prospects of a possible cease-fire, weapons pullback and prisoner exchange.
Fabius said the aim of the talks is to win an accord that works on the ground, "not just one on paper."
The continuing toll included at least nine people killed and 35 wounded in fresh fighting in eastern Ukraine, 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.
The city administration in rebel-held Donetsk said seven people were killed and 14 wounded in the fighting.
"The night of 11 to 12 February in Donetsk was tense," the administration said. "Powerful explosions and salvos could be heard periodically."
Also on Thursday morning, The International Monetary Fund has agreed to provide Ukraine with $17.6 billion to help support economic reforms.
IMF Managing Director Christine Lagarde said that "this new program offers an important opportunity for Ukraine to move its economy forward at a critical moment in the country's history."
Largarde says the reform plan "is an ambitious program, it is a tough program, and it is not without risk. But it is also a realistic program and its effective implementation — after consideration and approval by our executive board — can represent a turning point for Ukraine."
The negotiations opened Wednesday evening with a handshake between Ukrainian President Petro Poroshenko and Russian leader Vladimir Putin, who were meeting for the first time since October.
The meeting with German Chancellor Angela Merkel and French President Francois Hollande in the Belarusian capital was part of a diplomatic drive aimed at stopping the crisis.
"Today the peace process for Ukraine is all about Minsk and I hope that the meeting will fulfill our best expectations," Poroshenko told host Belarusian leader Alexander Lukashenko ahead of the talks.
"The entire world is waiting to see whether the situation moves toward de-escalation, weapons pullback, cease-fire, or ... spins out of control," Poroshenko said.
Poroshenko warned before the talks that he would introduce martial law, which would mark a significant escalation of the crisis, freeing up military resources for the fight in the east but also likely leading to the severance of foreign investment for cash-strapped Ukraine.
If the Minsk talks fail, President Barack Obama has warned that Washington may decide to start providing lethal weapons to Ukraine, a step many European leaders oppose for fear of getting drawn into open conflict with Russia.
Separatist negotiators meanwhile met on Wednesday elsewhere in Minsk to agree how to implement previous truce deals with representatives from Kiev, Moscow and mediators from the Organization for Security and Co-operation in Europe.
The most pressing element is the need to agree on an immediate ceasefire between the two sides that would see an end to the surge in fighting that has killed hundreds of civilians in recent weeks.
A key sticking point is whether a new deal will extend rebel control over 200 square miles of territory taken over the past month.
Moscow is also pushing for the separatist-held territories to be granted a large degree of autonomy, but Kiev only says that it is willing to decentralize some powers.
The fighting in eastern Ukraine has been relentless in recent weeks as the rebels have pushed deeper into government-held territory and Kiev forces have counter-attacked.
Poroshenko posted a statement saying he had made an impromptu visit early Wednesday to the eastern Ukrainian city of Kramatorsk, where Kiev says 16 people were killed and 48 wounded in a rocket strike a day earlier.
"We demand an unconditional peace," Poroshenko said. "We demand a cease-fire, a withdrawal of all foreign troops, and closing of the border. ... We will find a compromise within the country."