The leader of pro-Russian separatists in eastern Ukraine's Donetsk region has said that rebel forces will seek to take over the entire province and will not initiate peace talks with government forces.
The remarks by the leader of the self-proclaimed People's Republic of Donetsk, Aleksandr Zakharchenko, further clouded prospects for peace following days of intensified fighting that the United Nations said brought the death toll in the nine-month-old conflict above 5,000.
"We will advance to the very borders of the Donetsk Oblast," the Russian news agency Interfax quoted Zakharchenko as telling students in the rebel-held provincial capital on January 23.
He added that "if I see a threat from other sides, we will liquidate it," Interfax reported.
"From our side, there will be no more attempts to talk about a truce," Zakharchenko said.
Later on January 23, German Foreign Minister Frank-Walter Steinmeier accused Zakharchenko and pro-Russian separatist fighters of "nothing but warmongering" and insisted that rebels and Ukrainian forces begin withdrawing their heavy weapons away from the front line in the conflict.
Separatists Kyiv and NATO say have direct military support from Moscow hold parts of the Donetsk and Luhansk provinces, which border Russia to the east, but Ukraine controls much of the western parts of the two provinces.
NATO Secretary-General Jens Stoltenberg told Reuters on January 23 that the alliance has noted a "substantial increase in Russian heavy equipment" in Ukraine, including "tanks, armored vehicles, artillery, [and] advanced air-defense systems."
He added that he was prepared to meet with Russian Foreign Minister Sergei Lavrov on the sidelines of the Munich security conference in early February.
Zakharchenko's comments will deepen Western suspicions that Moscow is seeking to expand control in Ukraine after annexing the Crimean Peninsulafrom its neighbor in March and supporting the separatists.
A 12-point peace plan agreed in Minsk in September called for a cease-fire, which has been violated almost daily, and an agreement reached in Berlin on January 21 obliged both the rebels and government forces to pull heavy weapons back 15 kilometers from separation lines set in the Minsk deal.
Russian Foreign Minister Sergei Lavrov said on January 21 that the separatists had assured Moscow that they would cede ground that had taken beyond those lines.
The European Union urged both sides to "immediate cease hostilities" and withdraw heavy weapons in accordance with the Minsk agreement.
"The escalation of fighting and significant recent cease-fire violations, resulting from the actions of illegal armed groups in eastern Ukraine, have led to many deeply deplorable civilian as well as military casualties," said Maja Kocijancic, a spokeswoman for EU foreign policy chief Federica Mogherini.
She called for an "impartial investigation" into a blast that hit a trolleybus in the city of Donetsk on January 22, killing as many as 13 people in an attack each side blamed on the other.
Speaking in Florence, German Chancellor Angela Merkel called for implementation of the Minsk agreement.
She said a meeting of the "contact group" linking Ukraine, Russia, and the OSCE is "urgently" needed "so that we don't merely have something on paper but so that heavy armaments are withdrawn and the cease-fire is put back in place."
In Geneva,UN human rights spokesman Rupert Colville told a news briefing that 262 people were killed in the conflict in the past nine days, making it "the most deadly" period since the September 5 cease-fire deal.
"The significant escalation in hostilities has taken the toll to 5,086 individuals and we fear the real figure may be considerably higher," Colville said on January 23.
On January 22, rebel fighters paraded captured Ukrainian troops through Donetsk hours after the trolleybus attack, making them kneel near the site and subjecting them to verbal and physical abuse by what appeared to be angry residents.
Amnesty International issued a statement expressing concern over the incident, while European Parliament chief Martin Schulz tweeted, "Strongly condemn appalling parade of captured Ukrainian soldiers by rebels. Stooping so low makes rebels' cause all the more untenable."
Despite the September cease-fire and the pullback agreement reached in talks in Berlin between Lavrov and the foreign ministers of Ukraine, Germany, and France, fighting intensified at the bitterly contested Donetsk airport.
Ukrainian forces withdrew from most positions at the airport on January 21-22, losing control of an important foothold and symbolic prize near the city.
However, separatist defense spokesman Eduard Basurin said 24 rebel fighters were killed by a government rocket attack on the airport on January 23.
Zakharchenko said separatist forces were advancing toward at least three towns in the Donetsk region on January 23 and that rebels in the Luhansk region were also advancing.
In Kyiv, the government said rebels were on the offensive.
"Russian terrorist groups have essentially violated all prior cease-fire agreements... and are today assuming active offensive operations," National Security and Defence Council chief Oleksandr Turchynov told a televised government meeting.
Russia denies involvement in the conflict despite what Kyiv and NATO say is incontrovertible evidence it has sent troops into eastern Ukraine and provided the rebels with sophisticated weapons.
Russian President Vladimir Putin blamed Kyiv for the escalation of fighting, claiming that government forces were conducting "large-scale military action" against the separatists.