Russia has intensified its offensive operations on a long front, and Ukrainian sources have spoken of fierce battles on several axes, while Moscow attacked Slovakia after handing over Soviet-made fighter jets to Kiev.

Ukrainian military reports said on Friday that heavy fighting was taking place along a front stretching from the city of Liman in the Donetsk region of the Donbas region (eastern Ukraine) to Kobyansk in the Kharkiv region (northeast).

Fighting is reportedly taking place simultaneously around the city of Avdiivka near the Russian-controlled city of Donetsk, the administrative center of the province of the same name.

Reuters said Ukrainian forces were now focused on preventing Russian forces from advancing on a roughly 300-kilometre front stretching from Kobiansk in the north to Voglidar in the south.

Russian forces are continuing their military pressure in several axes in the Donbas region, including the city of Bakhmout, and on the outskirts of Kharkiv province, to make important progress in anticipation of a possible counteroffensive by Ukrainian forces this spring.

Russian forces continue to encircle the city of Avdiivka to the north and south, the Russian military website Rebar said, adding that they control the city of Novo Pakhmutka north of Avdiivka.

Ukrainian troops en route to Bakhmut (French)

Battles of Bakhmut

In Bakhmut, which has become the center of the fiercest fighting in the Donbas region, battles are still ongoing for control of the Bogdanovka and Orikhovo-Vasilyovka regions northwest of the city, according to Russia's Rebar website.

The site reported that the forces of the Russian Wagner Special Military Group are still advancing in the southern areas of Pakhmot, and spoke of fierce battles taking place for control of the Krasniyeh region southwest of the city.

Wagner's forces have recently taken control of the eastern part of Bakhmut and are trying to cut off the last supply routes for Ukrainian forces from the west.

Ukrainian ground forces commander Oleksandr Sirsky said on Thursday his forces would soon begin a counteroffensive in Bakhmut after withstanding Russia's all-winter military campaign.

Cersky stressed that the fighters of the Russian Wagner Group are losing a great deal of their strength and that they are running out of energy, explaining that his forces will soon take advantage of this opportunity as they did before near Kiev, Kharkiv and Kubiansk, when the Ukrainians launched counterattacks and regained control of large areas last year.

Bloomberg quoted US officials as saying that Ukrainian forces may seek in their upcoming offensive to cut the bridge linking Russia to Crimea, which Moscow annexed in 2014.

The General Staff of the Ukrainian Forces said that Russian forces yesterday launched 40 air strikes and bombarded with more than 200 rocket-propelled grenades Ukrainian army positions and civilian infrastructure in a number of Ukrainian towns, killing civilians.

The General Staff added that the Russian offensive operations are concentrated in the directions of the cities of Liman, Pakhmot, Avdievka and Marinka in addition to Shakhtar in the Donetsk region, and the Ukrainian General Staff said that its forces carried out 16 air strikes on the areas where Russian soldiers and military equipment are stationed and shot down Iranian-made "Shahid" drones and "Lancet".

France yesterday warned its citizens against traveling to Ukraine after the death of one of its nationals in mysterious circumstances near the city of Bakhmot.

Contract Campaign

At the same time, Bloomberg quoted officials familiar with the matter as saying that the Kremlin is seeking to sign 400,<> troops this year, mostly veterans and villagers. According to those sources, the ambitious contracting campaign will allow the Kremlin to avoid conscription as President Vladimir Putin's re-election campaign approaches.

Western and Ukrainian officials said the 300,<> Russian troops mobilized in the fall were all on the battlefield, though they had not been able to capture any major city in recent months.

The Kremlin backed down from plans to launch another offensive in Ukraine this spring after more territorial acquisition failed, and that the focus of Russian forces would be on blocking the Ukrainian offensive expected to begin soon.

Two MiG-29s of the Lubiland Air Force (Getty Images)

MiGs

Separately, Russia yesterday accused Slovakia of violating a contract by delivering Soviet-made MiG-29 fighter jets to Ukraine.

Under a 1997 agreement, Slovakia cannot transfer aircraft to another country without Russia's consent, the Federal Service for Military Technical Cooperation said in Moscow.

Russian authorities spoke of an "unfriendly act" and a violation of Bratislava's international obligations in accordance with the contract posted on the Russian Foreign Ministry's website.

The Slovak Defense Ministry said that on Thursday, 4 planes were transferred to Ukraine, with 9 more to follow in the next few weeks.

Most of the aircraft were supplied in the late eighties by the Soviet Union to the former Czechoslovakia.

Following the partition of Czechoslovakia, the Czech Republic and Slovakia divided the planes, and the latter acquired more aircraft from Russia in the nineties.

Days earlier, the Kremlin downplayed the value of planes that Slovakia and Poland had decided to deliver to Ukraine, saying Kiev was getting technology that had been dispensed with.

On military aid, EU leaders yesterday approved a plan to supply Ukraine with one million missiles within 12 months.

European defense and foreign ministers had earlier approved a two-billion-euro plan to supply Ukraine with one million artillery shells to be deducted from their stockpiles.

French President Emmanuel Macron said European leaders had contacted Ukrainian President Volodymyr Zelenskiy during their summit in Brussels to renew support for him so he could win the conflict in the face of what he called Russian aggression.