KYIV, Feb 20 - Delays in weapons deliveries from Western allies to Ukraine are opening a door for Russian battlefield advances, President Volodymyr Zelenskyy says, making the fight “very difficult” along parts of the front line where the Kremlin’s forces captured a strategic city last weekend ahead of the war’s second anniversary.

Zelenskyy and other officials have often expressed frustration at the slowness of promised aid deliveries, especially since signs of war fatigue have emerged. European countries are struggling to find enough stocks to send to Kyiv, and U.S. help worth $60 billion is stalled over political differences. That appears to be playing into the hands of Russian President Vladimir Putin.

Even so, more help is heading Ukraine’s way, as Sweden announced Tuesday its biggest aid package so far and Canada said it was expediting the delivery of more than 800 drones.

Zelenskyy, in his daily video address late Monday, said Russia has built up troops at some points along the 1,500-kilometer (930-mile) front line, apparently aiming to pounce on any perceived defensive weaknesses.

“They (the Russians) are taking advantage of delays in aid to Ukraine,” he said after visiting the command post in the area of Kupiansk, in the northeastern Kharkiv region, on Monday, The Associated Press reported.

He said Ukrainian troops keenly felt a shortage of artillery, air defense systems and long-range weapons.

Ukrainian forces withdrew from the strategic eastern city of Avdiivka during the weekend, where they had battled a fierce Russian assault for four months despite being heavily outnumbered and outgunned.

Putin on Tuesday congratulated his Defense Minister Sergei Shoigu on capturing Avdiivka and urged him to press Russia’s advantage.

Shoigu said the military launched up to 460 strikes on Avdiivka per day, equivalent to about 200 metric tons of explosives. “We got the enemy in such a state that it was forced to flee the unbearable conditions,” Shoigu said.

But Oleksiy Danilov, head of Ukraine’s National Security and Defense Council, said that while the situation on the battlefield is hard, especially due to a lack of ammunition, the situation on the eastern front is not catastrophic.

“We fight and will continue to fight,” he told news outlet Ukrainska Pravda. “We have only one request to our partners: to help with weapons, with ammunition, and with air defense.”

He claimed that Russia racked up heavy losses of troops and equipment in the fight for bombed-out Avdiivka. His claim could not be independently verified.

Analysts predicted a lull in Russian attacks in the Avdiivka area. The Kremlin’s forces will require time to “rest and refit,” the U.K. Ministry of Defense said in an assessment Tuesday.

Sweden, which is poised to join NATO, said Tuesday it will donate military aid to Ukraine worth 7.1 billion kronor ($681 million). That includes 30 boats, some of which are fast and powerful military assault craft, and underwater weapons.

The deal also includes artillery ammunition, Leopard tanks, shoulder-borne anti-aircraft defense systems, anti-tank missiles, grenade launchers, hand grenades and medical transport vehicles, as well as underwater drones and diving equipment.

“By supporting Ukraine, we are also investing in our own security,” Defense Minister Pål Jonson told a news conference in Stockholm. “If Russia were to win this terrible war, we would have significantly greater security problems than we have today.”

The Canadian government said Monday it will dispatch more than 800 drones to Ukraine starting as early as this spring. They are part of a previously announced 500 million Canadian dollars ($370 million) in military help for Ukraine.

Ukraine last year received $42.5 billion from foreign partners, of which $11.6 billion was in non-repayable grant aid, Ukraine’s Ministry of Finance said Tuesday.

The grant assistance was provided by the U.S., Japan, Norway, Germany, Spain, Finland, Switzerland, Ireland, Belgium, and Iceland, it said. The U.S. provided the biggest amount of non-repayable grant aid, with $11 billion.

Long-term concessional financing amounted to $30.9 billion, which included loans from the European Union ($19.5 billion), the International Monetary Fund ($4.5 billion), Japan ($3.4 billion), Canada ($1.8 billion), the U.K. ($1 billion), the World Bank ($660 million) and Spain ($50 million).

Ukraine shot down all 23 Shahed drones that Russia launched on Monday night over various regions of the country, the country’s air force said.

Air force spokesman Yurii Ihnat said Russian aircraft activity had dropped off after Ukraine recently shot down a number of enemy warplanes.

The air force commander, Mykola Oleschuk, said on Monday that his troops destroyed Su-34 and Su-35 bomber jets. Over the weekend he said that other Russian jets were shot down. (ap/ez)