KYIV, Ukraine>> Ukraine’s military chief said early Saturday that he’s withdrawing troops from the city of Avdiivka in eastern Ukraine, where outnumbered defenders have battled a Russian assault for four months.

The timing is critical as Russia is looking for a morale boost before Feb. 24, the second anniversary of Moscow’s full-scale invasion of Ukraine, and the March presidential election in Russia.

In a short statement posted on Facebook, Ukrainian commander Col. Gen. Oleksandr Syrskyi said he had made the decision to avoid encirclement and “preserve the lives and health of servicemen.”

The commander-in-chief added that troops were moving to “more favorable lines.”

“Our soldiers performed their military duty with dignity, did everything possible to destroy the best Russian military units, inflicted significant losses on the enemy in terms of manpower and equipment.

“We are taking measures to stabilize the situation and maintain our positions,” the statement read.

The withdrawal came a day after Ukrainian President Volodymyr Zelenskyy on Friday made another trip to western Europe, hoping to press his country’s Western allies to keep providing military support.

It was Syrskyi’s first major test since being appointed as Ukraine’s new army chief last week.

In his previous position as commander of Ukraine’s ground forces, he faced criticism for holding on to the city of Bakhmut for nine months, a siege that became the war’s longest and bloodiest battle and cost Ukraine dearly but also served to sap Russia’s forces.

In recent days, reports emerged that Ukrainian troops in Avdiivka faced a deteriorating situation.

Rodion Kudriashov, deputy commander of the 3rd Assault Brigade, said Friday that Ukrainian troops were still holding out against the onslaught of about 15,000 Russian soldiers, but he expected the situation would “soon become critical.”

“The enemy is trying to penetrate our defense and in some places to bypass our positions,” he told The Associated Press.

The 3rd Brigade said on its social media account Friday that its soldiers were at the huge Avdiivka Coke Plant. Russian warplanes have been dropping about 60 bombs a day, relentlessly shelling the area and launching assaults with armor and infantry, the brigade said.

A video showed dense black smoke over the factory, said to be caused by burning fuel oil reservoirs. The post said: “Poisonous smog spreads all over the plant.”

Russian media reported the Kremlin’s forces were making extensive use of plane-launched glide bombs, which fly at a shallower angle, to batter Ukrainian positions.

White House national security spokesman John Kirby said on Thursday that Russian forces were beginning to overwhelm Ukrainian defenses in the eastern city. He said Avdiivka is at risk of falling to Russia, a development he blamed “in very large part” on the fact that Ukrainian forces are running out of artillery ammunition.

The United States is Ukraine’s biggest supporter, but some $60 billion for Kyiv is being held up by political disagreements among American lawmakers.

Heavily fortified with a web of tunnels and concrete fortifications, Avdiivka lies in the northern suburbs of Donetsk, a city in a region of the same name that Russian forces partially occupy. Capturing Avdiivka could be a timely boost for Moscow and serve as a possible springboard for Russia to drive deeper into the region.