Moscow Thursday accused the U.S. of orchestrating a drone attack on the Kremlin, which was denied by Washington, and said Ukrainian sabotage within Russian borders had reached "unprecedented momentum."

Moscow said President Vladimir Putin was working from the Kremlin the day after the attack, which it said was a Ukrainian attempt to kill him.

"Decisions on such attacks are not made in Kyiv, but in Washington," Kremlin spokesperson Dmitry Peskov said.

"Kyiv only does what it is told to do... Washington should understand clearly that we know this," he said.

Ukraine has denied responsibility, with President Volodymyr Zelenskyy saying "We do not attack Moscow or Putin."

The U.S. has also denied any involvement.

"Peskov is just lying there, pure and simple," John Kirby, spokesperson for the White House National Security Council, said on MSNBC.

Throughout its more than year-long offensive in Ukraine, Moscow has maintained that Kyiv is taking orders from the U.S. – accusing the West of leading a war against Russia by proxy.

Another Ukraine ally, EU foreign policy chief Josep Borrell warned Moscow "not to use this alleged attack as an excuse to continue the escalation of the war".

'Unprecedented' sabotage

The Kremlin attack came as Russia prepares to mark one of its main holidays of May 9 – celebrating the Soviet victory over the Nazis – with a traditional military parade on Red Square.

It came after five days of apparent sabotage attacks, including trains derailed by explosions and massive fires in annexed Crimea.

On Thursday, Russia's southern Krasnodar and Rostov regions, both near Ukraine, reported drone strikes that caused fires.

And early Thursday evening, Russia-installed authorities in Crimea, a peninsula annexed by Russia in 2014, said their forces had downed a drone near an airbase in the region.

The Kremlin has insisted Moscow's May 9 parade will go ahead, despite the attacks in border regions and in the heart of Russian power, but under "strengthened" security.

Russian television on Thursday showed Putin in the Kremlin for the first time since the drone attack.

The Russian leader does not plan "any address on this topic," said his spokesperson.

Moscow did, however, acknowledge that the country was facing an "unprecedented" wave of sabotage.

Russia has opened a terrorism probe into the Moscow attack.

It has not released official images of the attack. Unverified social media images showed a drone hitting the Kremlin Senate building.

Peskov said "two copper sheets" on the dome of the 18th-century building had been damaged by fire.

"They have been or will be replaced, everything will be like new. There is no other damage."

'Criminal actions'

As Moscow accused the U.S. of planning the Kremlin attack, Ukraine's Zelenskyy arrived on a surprise visit to The Hague.

He visited the International Criminal Court, which in March issued an arrest warrant for Putin over the alleged illegal deportation of Ukrainian children.

"We all want to see a different Vladimir here," Zelenskyy said, referring to the Russian President, his namesake, who he believes "deserves to be sanctioned for his criminal actions here, in the capital of international law."

A special tribunal should be created to hold Russia to account for its "crime of aggression," he said.

"There should be responsibility for this crime. And this can only be enforced by the tribunal," Zelenskyy told diplomats and officials at the court.

The Netherlands has pledged both financial and military support to Ukraine since Russia launched its offensive in February 2022.

Zelenskyy, who also met Dutch Prime Minister Mark Rutte, said Ukraine was "realistic" that it would not be able to join NATO while still fighting Russia.

"But we want a very clear message that we will be in NATO after the war," he said.

Putin has used Ukraine's wish to join the alliance to justify launching his offensive.

Intense strikes

On the day of the alleged Kremlin attack, Ukraine said Russia had shelled the southern Kherson region, one strike hitting a supermarket.

At least 23 people died, and 46 were wounded in the strikes, officials said.

After the Kremlin accused Kyiv of attempting to kill Putin, Ukrainian authorities said they faced a new wave of strikes overnight.

The Ukrainian air force said Thursday that Russia had fired 24 attack drones overnight, 18 of which were downed. Authorities said there were no casualties.

Sergiy Popko, the head of the city of Kyiv's military administration, said "All enemy missiles and UAVs (unmanned aerial vehicles) were destroyed over Kyiv by air defense forces."

Popko said it was the third day of attempted strikes on Kyiv in May.

"Our city has not experienced such intensity of strikes since the beginning of this year," he said.