South Korea's president vowed to retaliate immediately against any potential provocations by North Korea in his Armed Forces Day speech Tuesday, as thousands of troops prepared to march through the capital in the country's first such military parade in 10 years.

The show of force comes as concerns grow that North Korea is seeking Russian help in expanding its nuclear arsenal in return for supplying Moscow with conventional arms exhausted by its war with Ukraine.

Thousands more refugees fled Nagorno-Karabakh on Tuesday as officials in the self-proclaimed republic said a fuel depot explosion the previous day had killed 20 people.

The Armenian government has warned of possible "ethnic cleansing" by Azerbaijan following its lightning offensive against the breakaway region last week.

North Korea will allow foreign nationals to enter the country from Monday, Chinese state media reported, after over three years of Covid-induced isolation.

Moscow on Monday accused Armenia of trying to sever ties after Yerevan accused Russian peacekeepers of failing to stop Azerbaijan's military offensive against Armenian separatists in Nagorno-Karabakh last week.

"The leadership in Yerevan is making a huge mistake by deliberately trying to destroy Armenia's multifaceted and centuries-old ties with Russia, and by holding the country hostage to the geopolitical games of the West," Russia's foreign ministry said.

Flying above enemy lines, a Ukrainian reconnaissance drone sends a clear image back to soldiers hiding in a basement a few kilometers away: A Russian armored vehicle is idling along a key logistics route, looking like easy prey in the artillery-scarred green landscape.

Then, in a flash, the image disappears, and the drone operator's screen is replaced by a jumble of black and white pixels.

Kosovo on Monday observed a day of mourning for the Kosovar Albanian police officer killed by Serb gunmen who then barricaded themselves in an Orthodox monastery in a siege that further raised tensions as the two wartime foes seek to normalize ties.

Flags were at half-staff on all public buildings in the capital Pristina to mourn Afrim Bunjaku. In the north, where most of Kosovo's ethnic Serb minority lives in four municipalities around Mitrovica, police were patrolling in search of the armed assailants after they left the monastery.

Thousands of Armenians streamed out of Nagorno-Karabakh after the Azerbaijani military reclaimed full control of the breakaway region, while Turkish President Recep Tayyip Erdogan visited Azerbaijan on Monday in a show of support to its ally.

The Azerbaijani military routed Armenian forces in a 24-hour blitz last week, forcing the separatist authorities to agree to lay down weapons and start talks on Nagorno-Karabakh's "reintegration" into Azerbaijan after three decades of separatist rule.

President Emmanuel Macron announced Sunday that France will end its military presence in Niger and pull its ambassador out of the country as a result of the coup that removed the democratically elected president.

Niger's junta said in response that the announcement signals a "new step towards the sovereignty" of the country.

Russia launched a major aerial attack on southern Ukraine overnight, the Ukrainian military said Monday, hitting Odesa port and destroying grain stores.

Russia "attacked the south of the country again", the Defence Forces of the South of Ukraine said on the messaging platform Telegram.

Armenian Prime Minister Nikol Pashinyan on Sunday took a veiled swipe at long-standing ally Russia, calling his country's current foreign security systems "ineffective."

"The systems of external security in which Armenia is involved are ineffective when it comes to the protection of our security and Armenia's national interests," Pashinyan said in a televised address aired days after Azerbaijan's resounding victory in the disputed Nagorno-Karabakh region.