Rescuers in Kyiv said Wednesday that the death toll from a major Russian attack on Ukraine's capital the previous day had risen to 21, with more than 130 people wounded.
Russia launched dozens of drones and missiles at Kyiv early Tuesday in what President Volodymyr Zelensky called "one of the most horrific attacks" on the capital of the three-year war.
"In total, 21 people died in the capital and 134 people were injured," Ukraine's state emergency service wrote on Telegram.
It added that 16 bodies had been recovered from the rubble of a single nine-story apartment building in the Solomyansky district.
The previous death toll given by Kyiv's mayor was 14.
Zelensky said 440 drones and 32 missiles were launched in the strikes nationwide and urged the international community not to "turn a blind eye".
The Russian defence ministry said it had conducted precision strikes on "military-industrial facilities in the Kyiv region," in a statement similar to those released after other major attacks.
More than three years into its full-scale invasion of Ukraine, Moscow has stepped up attacks despite efforts by the United States to broker a ceasefire.
Talks have stalled. Moscow has rejected the "unconditional" truce demanded by Kyiv and its European allies, while Ukraine has dismissed Russia's demands as "ultimatums".
NK to send army builders, deminers to Kursk
North Korea will send military builders and sappers to help restore Russia's Kursk region after Ukraine's incursion, Moscow's security chief said, in a fresh sign of deepening ties between the two countries.
Sergei Shoigu, head of Russia's Security Council, was in Pyongyang for the second time this month for talks with leader Kim Jong Un on the one-year anniversary of the signing of a sweeping military deal between the two countries, state media from both countries reported.
North Korea has become one of Russia's main allies during its more than three-year-long Ukraine offensive, sending thousands of troops and container loads of weapons to help the Kremlin oust Ukrainian forces from Kursk.
Now, Pyongyang is going to dispatch more specialist military forces to help with reconstruction efforts, with both sides reaching a deal "on continuing constructive cooperation", the TASS news agency quoted Shoigu as saying.
North Korea will send "a division of builders, two military brigades -- 5,000 people" as well as 1,000 deminers to the Kursk region, Shoigu said.
"This is a kind of fraternal assistance from the Korean people and leader Kim Jong Un to our country," he was quoted as saying.
Russia and North Korea signed the military deal last year, including a mutual defence clause, during a rare visit by Russian leader Vladimir Putin to the nuclear-armed North.
Around 600 North Korean soldiers have been killed and thousands more wounded fighting for Russia, according to South Korean lawmaker Lee Seong-kweun, citing the country's intelligence service.
Pyongyang in April confirmed for the first time that it had deployed troops to support Russia's war in Ukraine -- and admitted that its troops had been killed in combat.
North Korean state media said Kim had confirmed plans for further cooperation but did not provide details.
Kim and Shoigu discussed "items of immediate cooperation" as well as "long-term plans" to carry out "important matters agreed by the heads of states of the two countries through the exchanges of personal letters for several weeks," the Korean Central News Agency (KCNA) said.
Kim also expressed North Korea's "steadfast" will to "invariably and unconditionally support" Russia's policy to defend its "state sovereignty and territorial integrity".
Plans to honour North Korean soldiers who died "in the operations for liberating the Kursk area" were also discussed, KCNA said.
- 'Issue of concern' -
Seoul's foreign ministry on Wednesday said the "acceptance and employment of North Korean overseas workers constitute a clear violation of UN Security Council resolutions".
"The South Korean government expresses serious concern over the continued illicit cooperation between Russia and North Korea and urges an immediate halt to such activities," it said in a statement sent to AFP.
New South Korean President Lee Jae-myung, who took office this month following a snap election triggered by his predecessor's disastrous martial law bid in December, has pledged a more conciliatory approach toward Pyongyang.
Lee's administration recently halted the loudspeaker broadcasts the country had resumed last year in response to a wave of trash-laden balloons sent by Pyongyang.
In turn, North Korea has stopped transmitting bizarre, unsettling noises along the border that had been a major nuisance for residents in the area.
"The mention of building infrastructure to expand various exchanges and cooperation appears intended to emphasise the possibility of increased interaction" between Russia and North Korea, Hong Min, a senior analyst at the Korea Institute for National Unification, told AFP.
Hong said railway links along the North Korea-Russia border are currently being restored, with the possible launch of air routes also under consideration.