FILE In this file photo taken on Friday, Aug. 29, 2014, Russian Foreign Minister Sergey Lavrov speaks to the media during his and Iranian Foreign Minister Mohammad Javad Zarif after their talks in Moscow, Russia . Russiaâ€™s foreign minister Sergey Lavrov urged those holding a new round of talks Monday on easing Ukraineâ€™s crisis to push for a cease-fire between Ukrainian government troops and pro-Russian separatists.(AP Photo/Alexander Zemlianichenko, file)
Pro-Russian rebels prepare arms for the the assault on the positions of Ukrainian army in Donetsk airport, eastern Ukraine, Sunday, Aug. 31, 2014. Russian President Vladimir Putin on Sunday called on Ukraine to immediately start talks on a political solution to the crisis in eastern Ukraine. Hours later, Ukraine said a border guard vessel operating in the Azov Sea was attacked by land-based forces. (AP Photo/Mstislav Chernov)
A Pro-Russian rebel prepares arms for the the assault on the positions of Ukrainian army in Donetsk airport, eastern Ukraine, Sunday, Aug. 31, 2014. Russian President Vladimir Putin on Sunday called on Ukraine to immediately start talks on a political solution to the crisis in eastern Ukraine. Hours later, Ukraine said a border guard vessel operating in the Azov Sea was attacked by land-based forces. (AP Photo/Mstislav Chernov)
MOSCOW — Diplomats at a new round of talks on easing the crisis in Ukraine must push for an immediate, unconditional cease-fire between Ukrainian government troops and pro-Russian separatists, Russia's foreign minister said Monday.
The talks later Monday in Minsk, the Belarusian capital, come as Ukrainian troops are facing a resurgent rebel force. In the past week, the rebels have opened a new front along the southeastern Azov Sea coast and are pushing back after losing ground in the previous several weeks.
Russian Foreign Minister Sergey Lavrov also said Russia would not intervene militarily in Ukraine, defying reports by the Ukrainian government, NATO and Western nations that Russia has already sent troops, artillery and tanks across Ukraine's southeast border to reinforce the separatists.
"There will be no military intervention," Lavrov told students at Moscow State Institute of International Relations on Monday, the first day of classes for schools and universities across the country. "We call for an exclusively peaceful settlement of this severe crisis, this tragedy."
The envoys, who last met in July, included representatives of Ukraine, Russia and the Organization for Security and Cooperation in Europe. A separatist leader, Andrei Purgin, also was to take part.
Purgin told the Interfax news agency that the separatists' priority was to win recognition of their independence in eastern Ukraine, which has a large Russian-speaking population. He said they also were willing to discuss the exchange of prisoners and a temporary cease-fire.
On Monday, Ukrainian National Security Council spokesman Col. Andriy Lysenko said Ukrainian forces had been ordered to retreat from the airport in Luhansk, the second-largest rebel-held city, in the face of an intensifying assault that he blamed on "professional artillery gunmen of the Russian armed forces."
Russia consistently denies allegations that it has sent troops or equipment into Ukraine. But Lysenko said Monday that "not less than four battalions and tactical groups of the Russian armed forces are active in Ukraine."
A battalion consists of about 400 soldiers.
The assault on the Azov Sea coast that began last week has raised concerns that the rebels are aiming to establish a land corridor from Russia to Crimea, the Black Sea peninsula that Russia annexed in March.
On Sunday, missiles were fired from the shore at two Ukrainian coast guard cutters about 3 miles (5 kilometers) out to sea, sinking one of them, Lysenko said. He said eight crewmen were rescued, but the Interfax news agency cited a spokesman for the border guards' service as saying two crewmen were missing and seven were rescued.
Fighting in eastern Ukraine between the separatists and the Ukrainian government in Kiev began in mid-April after the annexation of Crimea. The fighting has killed nearly 2,600 and forced over 340,000 to flee their homes, according to the U.N.
Jim Heintz in Kiev, Ukraine, contributed to this report.