Ukraine Sounds Warning Over Russian Troops Massing at Front Line

Ukrainian President Volodymyr Zelensky said 50,000 Russian troops were massing at the border near the Sumy region of northeastern Ukraine and Moscow may be preparing for a large-scale summer offensive.

Kyiv's forces have been battling in Russia's Kursk region since a cross-border offensive last summer, but they have been forced back by Moscow's recent advances. Russia has hailed the recapture from Ukrainian forces of a number of Russian towns and villages.

"Their largest, strongest forces are currently on the Kursk front to push our troops out of the Kursk region and to prepare offensive actions against the Sumy region," Zelensky said on Tuesday ahead of his visit to Germany, Sky News reported.

Trump 'Not Happy' With Putin

U.S. President Donald Trump expressed increasing frustration with Russian President Vladimir Putin, calling him "CRAZY!" on Sunday after deadly missile strikes hit Ukrainian cities. President Trump also expressed annoyance with Zelensky's rhetoric.

Trump is attempting to broker peace between Russia and Ukraine, but progress is slow, and he has said he would walk away if he saw that no deal could be made.

"I'm not happy with what Putin is doing," the president said on Sunday.

"He's killing a lot of people, and I don't know what the hell happened to Putin. I've known him a long time. Always gotten along with him, but he's sending rockets into cities and killing people, and I don't like it at all.

"We're in the middle of talking, and he's shooting rockets into Kyiv and other cities. I don't like it at all."

Further direct talks between Russia and Ukraine are due after their first set of negotiations in more than three years on May 16 produced only a mass prisoner swap and vague statements from the Russian delegation about working towards a ceasefire.

Russia has said it will only agree to a peace deal that addresses what it calls the "root causes" of the conflict, namely Ukrainian ambitions to join the U.S.-led NATO defensive alliance and policies that restrict the expression of Russian culture inside Ukraine.

But Ukraine accuses Russia of seeking to seize control of the country and remove its sovereignty in an imperial war of aggression.

Russia-Ukraine Fighting Continues

Meanwhile, fighting has continued along the approximately 1,000-kilometer (620-mile) front line, and both sides have conducted deep strikes. Russia launched its biggest drone attack of the war against Ukraine on Sunday.

Russian air defenses downed 296 Ukrainian drones over 13 Russian regions late Tuesday and early Wednesday, Russia's Defense Ministry said, in what appeared to be one of the biggest Ukrainian drone assaults of the war.

Moscow Mayor Sergei Sobyanin said air defenses shot down 33 Ukrainian drones heading toward the capital.

Andrei Vorobyov, the governor of the Moscow region, said that 42 drones were downed. He said that drone fragments damaged three residential buildings in the village of Troitskoye, but no one was hurt.

Moscow airports delayed or diverted hundreds of flights.

Overnight, Russian forces launched an attack on Ukraine using five Iskander ballistic missiles, one guided air-launched missile and 88 drones, Ukraine's Air Force said Wednesday. Air defense units shot down 34 drones, and 37 drones were jammed.

Ukraine's railway infrastructure and equipment in the Kharkiv, Donetsk and Sumy regions also came under fire overnight and Wednesday morning, Ukraine's state railway company Ukrzaliznytsia said. No casualties were reported.

In Kharkiv region, railway traffic was temporarily suspended so that police and emergency workers could clear debris from a downed drone that landed on the tracks.

In Sloviansk in the Donetsk region, the attack shattered windows at the station building, and drone debris slightly damaged a train car.

This article includes reporting by The Associated Press.