The Kremlin has confirmed that Russian President Vladimir Putin will take part in talks on the conflict in Ukraine with the leaders of Ukraine, Germany, and France in the Belarusian capital on February 11.
In a statement on its website, the Kremlin said Putin "is traveling today on a visit to Minsk, where he will take part in negotiations" with Ukrainian President Petro Poroshenko, French President Francois Hollande, and German Chancellor Angela Merkel.
The planned meeting is part of a diplomatic push, led by Merkel and Hollande, to end a conflict that has killed more than 5,350 people in eastern Ukraine since April and severely strained Moscow's relations with the West.
Russian officials, quoted anonymously during preliminary meetings and in the hours ahead of the leaders' gathering, appeared to be pressing hard to suggest that a deal was all but imminent.
But those reports were disputed by less optimistic diplomats and negotiators quoted in Western media.
Heavy fighting persisted ahead of the scheduled meeting.
WATCH: Reuters video of the scene where a shell struck a bus station in the rebel-controlled city of Donetsk on February 11, killing at least two people and wounding several others:
Putin and other officials had said earlier that several issues needed to be cleared up before the talks could be held.
French Foreign Minister Larent Fabius said on February 11 that the Minsk meeting "is really a last-chance negotiation."
Ukrainian President Petro Poroshenko on February 10 said, "Tomorrow's meeting in Minsk offers one of the last chances to declare an unconditional cease-fire and pull back heavy artillery."
German Chancellor Angela Merkel and French President Francois Hollande plan to meet with Putin and Poroshenko in the Belarusian capital, but doubts clouded its chances amid a surge in fighting in eastern Ukraine.
Early on February 11, news reports said at least two people were killed when a shell hit a bus station in the center of rebel-controlled Donetsk in eastern Ukraine. More were said to have been injured.
U.S. President Barack Obama spoke by telephone with both Putin and Poroshenko on February 10, the eve of the planned meeting.
The White House said Obama urged Putin to seize the opportunity of the Minsk peace talks to reach a peaceful resolution to the conflict, which has killed more than 5,300 people.
In the call to Putin, Obama reiterated U.S. support for Ukraine's sovereignty and emphasized the importance of reaching a diplomatic resolution, according to the White House.
"However, if Russia continues its aggressive actions in Ukraine, including by sending troops, weapons, and financing to support the separatists, the costs for Russia will rise," the White House said in a statement.
The Kremlin said the two presidents noted the necessity to safeguard rights of inhabitants of all Ukrainian regions, including the Russian-speaking ones in the east.
A Kremlin statement said Putin and Obama highlighted the need for a political solution to the "internal" conflict in Ukraine to swiftly end the bloodshed there.
Western governments accuse Moscow of arming, funding, and otherwise aiding the pro-Russian militants.
Poroshenko's office said he and Obama expressed hope that the Minsk summit would bring a halt to fighting.
Representatives of Ukraine, Russia, the Organization for Security and Cooperation in Europe (OSCE), and separatist-held regions of eastern Ukraine held a meeting of the so-called Contact Group on the eve of the talks to lay the groundwork for the summit, while senior officials from the four nations were holding parallel talks.
Russian Ambassador to Ukraine Mikhail Zurabov, former Ukrainian President Leonid Kuchma, OSCE special representative Heidi Tagliavini, and the authorized representatives from the two separatist regions -- Denis Pushilin from Donetsk and Vladislav Deinego from Luhansk, were all in the Belarusian capital for the February 10 talks ahead of the leaders' summit.
The Contact Group is the mechanism for talks which produced a September 5 agreement on a cease-fire, which failed to end the violence in east Ukraine.
The separatists used the meeting to submit settlement proposals, but Pushilin said on the separatists website that "it is too soon to speak about a cease-fire."
Meanwhile, Hollande said, "We are going to Minsk with the firm will to succeed, without being certain that we can do so," adding that he and Merkel were committed to doing everything possible to achieve "an agreement, a global settlement."
Hollande said a deal was also important for "a strong resumption of trade," which was hit by Western sanctions against Moscow and Russian countersanctions.
France has suspended delivery of a helicopter-carrying warship it agreed to sell to Russia until progress was made toward settling the Ukraine crisis.
German Foreign Minister Frank-Walter Steinmeier spoke by phone with his Russian and Ukrainian counterparts.
"I hope that none of those involved in the fighting will push things so far that Minsk is called into question by an explosion of violence in the final hours," Steinmeier said.
The EU foreign policy chief, Federica Mogherini, told the European Parliament in Strasbourg on February 10, "we have to do all that we can to make [the Minsk talks] work."
Russian President Vladimir Putin's spokesman, Dmitry Peskov, told the Russian News Service radio station that any talk about imposing new sanctions on Russia or arming the Ukraine government would destabilize the situation.
On February 9, Obama said after talks with Merkel in Washington that he was looking into the option of sending lethal defensive weapons to Kyiv "if diplomacy fails."
Meanwhile, fighting has surged in eastern Ukraine as government forces and pro-Russian rebels try to make gains ahead of the tentative summit.
Officials said separatists rebels fired rockets on a key military base and a residential area in the eastern city of Kramatorsk, killing at least 15 civilians and wounding more than 60.
The Kyiv-controlled Donetsk regional administration said the rockets were fired from the separatist-held area of Horlivka, which is about 50 kilometers from Kramatorsk.
But Eduard Basurin, a self-proclaimed separatist defense official, said the rebels "did not strike Kramatorsk" and contended that it was out of their range.
Ukraine's volunteer Azov Battalion said on social media on February 10 that it had captured several villages northeast of Mariupol, pushing Russian-backed separatists away from the strategic Azov Sea port city.
On February 9, rebel military spokesman Eduard Basurin said separatist forces had surrounded the strategic town of Debaltseve, site of a railway hub, cutting it off from a major highway.
Most of Debaltseve's 25,000 residents have been evacuated.
Government-controlled Debaltseve which straddles a transport junction between the rebel-held provincial capitals of Donetsk and Luhansk, has been the scene of fierce fighting in recent weeks.