TOP HEADLINES

• The refusal of Ukraine and NATO powers to recognize Moscow's authority over Crimea represents a "systemic threat" for Russia, former Russian president Dmitry Medvedev said. READ MORE BELOW

• Russia is preparing for the next offensive stage in Ukraine, according to a Ukrainian military official, after Moscow said its forces would step up military operations in "all operational areas." Russian rockets and missiles have pounded cities in strikes that Kyiv says have killed dozens in recent days. READ MORE BELOW

• The British defense ministry backed up these claims by saying Russia is reinforcing its defensive positions across the areas it occupies in southern Ukraine.

• Major crude oil producers have spare capacity and are likely to boost supplies following US President Joe Biden's visit to the Middle East, said a senior American energy envoy. Oil prices rocketed to their highest levels since 2008, climbing above $139 a barrel in March, after the United States and Europe imposed sanctions on Russia over its war with Ukraine.

• Russian aircraft shot down a Ukrainian MI-17 helicopter near Sloviansk and SU-25 aircraft in the Kharkiv region, Russia's defense ministry said.

• Russia has increased the quota for its exports of sunflower oil and sunflower meal, the government said on Sunday, citing sufficient domestic supplies.

• Russian missiles hit industrial facilities at a strategic city in southern Ukraine on Sunday as Moscow continued efforts to expand its gains in the country's east.

• A Ukrainian munitions cargo plane crashed near the city of Kavala in northern Greece late on Saturday, killing the crew members on board. The plane was en route to Bangladesh. READ MORE HERE

IN DETAIL

Refusal to recognize Moscow's authority over Crimea is "systemic threat" for Russia

The refusal of Ukraine and NATO powers to recognize Moscow's authority over Crimea represents a "systemic threat" for Russia, former Russian president Dmitry Medvedev said.

Russia claimed the Black Sea peninsula of Crimea from Ukraine in 2014 after a pro-Moscow president in Kyiv was toppled amid mass street protests. Moscow then also backed pro-Russian armed separatists in the Donbas region of eastern Ukraine.

"If any other state, be it Ukraine or NATO countries, believes that Crimea is not Russian, then this is a systemic threat for us," Medvedev told World War II veterans, the Interfax news agency reported.

"This is a direct and an explicit threat, especially given what had happened to Crimea. Crimea returned to Russia," said Medvedev, who now serves as deputy chairman of the Russian Security Council.

His comments were aired a day after a Ukrainian official suggested that Crimea, which most of the world still recognizes as part of Ukraine, could be a target for  American-made HIMARS missiles, recently deployed by Kyiv as it battles Russian forces.

Crimea is of particular strategic importance to Russia as it includes the headquarters of its Black Sea fleet at Sevastopol.

Ukraine says Russia preparing for next stage of offensive 

Russia is preparing for the next stage of its offensive in Ukraine, a Ukrainian military official said, after Moscow said its forces would step up military operations in "all operational areas."

Russian rockets and missiles have pounded cities in strikes that Kyiv says have killed dozens in recent days.

"It is not only missile strikes from the air and sea," said Vadym Skibitskyi, a spokesman for Ukrainian military intelligence. "We can see shelling along the entire line of contact, along the entire front line. There is an active use of tactical aviation and attack helicopters. Clearly preparations are now underway for the next stage of the offensive."

The Ukrainian military said Russia appeared to be regrouping units for an offensive toward Sloviansk, a symbolically important city held by Ukraine in the eastern region of Donetsk.

Ukraine says at least 40 people have been killed in Russian shelling of urban areas in the last three days, as the war intensifies.