All the latest development from the war in Ukraine.
Romanian President Klaus Iohannis denounced "the serious security risks in the Black Sea" on Monday after Russia bombed port facilities on the Danube, on the border between Romania and Moldova.
"I strongly condemn the recent Russian attacks on Ukrainian civilian infrastructure on the Danube, very close to NATO member Romania", Mr Iohannis wrote on Twitter.
Earlier in the day, images on social networks showed the Ukrainian port of Reni on the Danube being hit by a drone attack.
Ukrainian authorities later confirmed a four-hour blitz by Russian drones on port infrastructure in the Odesa region in the south of the country. The Ukrainian port city of Reni, which faces Romania, also borders Moldova.
"This recent escalation is also affecting the transit of Ukrainian grain and therefore global food security", said Iohannis.
The Odesa region, strategic for Ukrainian exports, is regularly targeted by Russian strikes.
Tensions increased in the Black Sea after the expiry last Monday of a grain agreement, which was crucial for maintaining world food security as it allowed for Ukrainian cereals exports.
'Ukraine has regained half of occupied land' – US official
Ukraine has recaptured half the territory seized by Russia in the initial phases of the war, US Secretary of State Antony Blinken said on Sunday.
In an interview with CNN, Blinken added the counteroffensive, still in its early phases, will get harder for Volodymyr Zelenskyy and his troops.
"It is tough. It will not play out over the next week or two. We're still looking I think at several months," he said.
Zelenskyy has previously termed the counteroffensive's progress as "slower than desired," asking for more aid in arms and ammunition from its allies.
Such requests come to fruition, with the US supplying cluster munition, and a group of 11 nations agreeing to provide F-16 fighter jet training.
Blinken said he believes Ukraine will eventually be able to secure F-16 jets if the air force is "properly trained" and is able to "use them in a smart way."
Kyiv has not been guaranteed the delivery of F-16 jets, since none of its allies have committed to sending warplanes.
Zelenskyy vows Odesa cathedral attack retaliation
Ukrainian leader Volodymyr Zelenskyy promised to strike Russia for a deadly attack on Odesa that wounded 22 people
"Missiles against peaceful cities, against residential buildings, a cathedral," Zelenskyy said. "There will definitely be a retaliation against Russian terrorists for Odesa."
The attack destroyed the Orthodox Savior and Transfiguration Cathedral under UNESCO protection in the historic city centre, which Kyiv called a "war crime that will never be forgotten and forgiven."
Andriy Palchuk, the archdeacon of the cathedral, told AFP that both people in the cathedral at the time of the attack survived.
Moscow said it had hit all its intended targets in the Odesa strike, claiming the sites were being used to prepare "terrorist acts" against Russia.
Odesa has been bombed several times since the start of the invasion. In January, the United Nations cultural agency UNESCO designated the historic centre of the city as a World Heritage in Danger site.
'Counteroffensive has failed,' claims Putin
Russian President Vladimir Putin told his Belarusian counterpart Alexander Lukashenko that the Ukrainian counteroffensive had failed on Sunday.
The two met for the first time since Lukashenko helped broker a deal to end a mutiny by Wagner fighters last month.
Putin told the Belarusian leader that an ongoing counteroffensive by Ukrainian forces to push back his country's troops had "failed".
"There is no counteroffensive," Lukashenko said, according to the Russian TASS news agency before being interrupted by Putin: "There is one, but it has failed."
A video posted on Sunday by Lukashenko's press service showed the two longtime leaders arriving at Saint Petersburg's Konstantinovsky palace together ahead of scheduled talks, which Putin has said will last for two days.
Russia blames Ukraine's cluster munitions for journalist's death
Russia has blamed US-supplied cluster munitions for the death of a Russian war correspondent in the southern Zaporizhzhia region.
RIA news' war correspondent Rostislav Zhuralev was killed on Saturday with three other journalists injured in the frontline, following an artillery attack.
Zhuralev died on the way to the hospital, the Russian defence ministry said, adding the others were mildly injured.
“As a result of a strike by the Ukrainian army using cluster munitions, four journalists were wounded,” the Russian army said in a statement.
The Russian foreign ministry reacted angrily to the incident, calling it a "heinous crime" and "criminal terror" committed by Kyiv, on the back of Western support.
“Those responsible for the brutal reprisal against a Russian journalist will inevitably suffer well-deserved punishment,” foreign ministry spokesperson Maria Zakharova said.
Zakharova echoed the defence ministry's sentiments, hinting at a possible retaliation for the killings done by cluster bombs.
Reports of Ukraine's use of cluster munitions came from Russia's Belgorod region as well. with Governor Vyacheslav Gladkov claiming a civilian village close to the Ukrainian border was targeted.
"21 artillery shells and three cluster munitions from a multiple-launch rocket system were fired at the village of Zhuravlevka,” Governor Gladkov said.
Russia's claims could not be independently verified.
Russia thwarts Ukrainian drone strike on Moscow
Russia said it foiled a Ukrainian drone attack on Moscow in the early hours of Monday.
The Russian Defence Ministry said a "terrorist" attack from Kyiv was prevented by the air force, without significant damage in the capital.
“A Kyiv regime attempt to carry out a terrorist act using two drones on objects on the territory of the city of Moscow was stopped,” the statement said.
One of the two drones landed near the defence ministry, according to Russian news agency TASS.
Drone attacks in the Russian capital have been a concern, despite it being far from the front. One drone hit the Kremlin in May, provoking an increased air defence around the city, though some suggested it might be an inside job.
The attacks followed Zelenskyy's vow to "retaliate" against the attack on the Odesa cathedral. Ukraine has not commented on the incident yet.