Ukraine President Volodymyr Zelenskyy said he spoke by phone with U.S. President Joe Biden about Washington’s future support for Kyiv, and Russian President Vladimir Putin visited a military base near the Ukrainian border, as the warring countries laid plans for the winter and next year’s combat operations.

Almost 20 months of war have sapped both sides’ military resources. The fighting is likely to settle into positional and attritional warfare during the approaching wintry weather, analysts say, with little change along the more than 1,000-kilometer (600-mile) front line.

Zelenskyy said late Thursday he spoke to Biden about “a significant support package” for Ukraine. Western help has been crucial for Ukraine’s war effort.

Putin visited late Thursday the headquarters of Russia’s Southern Military District, less than 100 kilometers (60 miles) from Ukraine’s southeastern border, where he was briefed on the war by the chief of the General Staff, Valery Gerasimov, the Kremlin said.

With uncertainty over the scale of Kyiv’s future Western aid, and after Ukraine’s five-month counteroffensive sapped Russian reserves but apparently only dented Russian front-line defenses, the two sides are scrambling to replenish their stockpiles for 2024.

Ukraine has been expending ammunition at a rate of more than 200,000 rounds per month, according to Jack Watling, a senior research fellow at the Royal United Services Institute think tank in London.

“Sufficient ammunition to sustain this rate of fire is not going to be forthcoming as NATO stockpiles deplete, and production rates for ammunition remain too low to meet this level of demand,” Watling wrote in an assessment published late Thursday.

Meanwhile, Russian production “has turned a corner,” he said. Moscow’s domestic ammunition production is growing quickly, at more than 100 long-range missiles a month compared with 40 a month a year ago, for example, according to Watling.

Also, Russia is reported to be receiving supplies from Iran, North Korea and other countries.

Though Ukraine’s counteroffensive has not made dramatic progress against Russia’s formidable defenses, it has suppressed the Kremlin’s forces and Kyiv is looking to keep up the pressure.

That will help stretch Russia’s manpower resources that are already under strain, according to the Institute for the Study of War, a Washington think tank.

It said in its latest assessment that “Russian forces largely lack high-quality reserves and are struggling to generate, train and soundly deploy reserves to effectively plug holes in the front line and pursue offensive operations.”

(AP)