A glance into Russia-Ukraine war as it enters 4th month

Russia heads into the fourth month of its invasion of Ukraine today with no end in sight to the fighting that has killed thousands, uprooted millions and reduced cities to rubble.

After abandoning its assault on the capital, Kyiv, Russia is pressing on in the east and south in the face of mounting sanctions and a fierce Ukrainian counter-offensive bolstered by Western arms.

The war expers say the Russians have failed to achieve their objectives and how the war will conclude remains unclear.

CNN describes  what has happened in several key areas since the war began as the war now deeps into its second phase.

Major cities

Donbas

After weeks of intense fighting, Ukraine‍‍`s eastern Donbas region is "completely destroyed." But the official said NATO believes momentum has shifted significantly in favor of Ukraine.

Kharkiv

Ukrainian forces have beaten back Russia‍‍`s assaults in Ukraine‍‍`s second city of Kharkiv, and advanced toward the border in several places north and east of the city.

Kherson

Every day, hundreds, or even thousands, of people are trying to flee the Russian-occupied region of Kherson in southern Ukraine.

Mariupol

Mariupol, a port city on the Sea of Azov, finally fell to Russian forces after weeks of relentless bombardment.

Bucha

More evidence of potential Russian war crimes is emerging in Bucha, the northern Ukrainian city near Kyiv, the capital. An investigation by The New York Times alleged that Russian paratroopers carried out summary executions of at least eight Ukrainian men in Bucha on March 4.

Major development 

Diplomats return

Foreign diplomatic missions started coming back to life in Kyiv this week, after diplomats fled the city en masse at the beginning of the conflict.

A massive aid package

US lawmakers passed a bill Thursday that will send roughly $40 billion to Ukraine to pay for military and humanitarian aid, including funding that will assist Ukrainian military and national security forces, help replenish stores of US equipment sent to Ukraine and provide public health and medical support for Ukrainian refugees.

Nordic developments

Russia stopped sending natural gas to Finland on May 21, just days after it and Sweden applied to join NATO. Most NATO members appear ready to support both bids, except for Turkey.

1st war crimes trial

Russian soldier Vadim Shishimarin, 21, is sentenced to life in prison by a Ukrainian court in Kyiv on May 23. He was convicted of killing an unarmed civilian. It was the first war crimes trial arising from Russia‍‍`s invasion.

Reuters has listed some key events in the conflict so far:

* Feb. 24: Russia invades Ukraine from three fronts in the biggest assault on a European state since World War II. 

* Feb. 25: Ukrainian forces battle Russian invaders in the north, east and south. 

* March 1: Russia hits a TV tower in Kyiv and intensifies its long-distance bombardment of Kharkiv in the northeast and other cities.

* March 2: Russian forces start a siege of the southeastern port of Mariupol, seen as vital to Russian attempts to link the eastern Donbas region with Crimea, the Black Sea peninsula Moscow seized in 2014.

Russian troops reach the centre of the Black Sea port of Kherson, the first large urban centre captured.

* March 4: Russian forces seize Zaporizhzhia nuclear power plant, Europe‍‍`s biggest. NATO rejects Ukraine‍‍`s appeal for no-fly zones, saying they would escalate the conflict.

*March 8: Civilians flee the northeastern city of Sumy in the first successful humanitarian corridor agreed. 

* March 9: Ukraine accuses Russia of bombing a maternity hospital in Mariupol, burying people in the rubble. 

* March 13: Russia extends its war deep into western Ukraine, firing missiles at a base in Yavoriv near the border with NATO member Poland.

* March 16: Ukraine accuses Russia of bombing a Mariupol theatre where hundreds of civilians are sheltering. Moscow denies it.

* March 30: More than 4 million people have fled Ukraine, the UNHCR says.

* April 3/4: Ukraine accuses Russia of war crimes after a mass grave and bodies of people shot at close range are found in the recaptured town of Bucha. The Kremlin denies responsibility and says images of bodies were staged.

* April 8: Ukraine blames Russia for a missile attack on a train station in Kramatorsk that killed at least 52 people trying to flee the looming eastern offensive. Russia denies responsibility.

* April 14: Russia‍‍`s lead warship in the Black Sea, the Moskva, sinks after what Ukraine says was a missile strike. Russia blames an ammunition explosion. 

* April 18: Russia launches its eastern assault, unleashing thousands of troops in what Ukraine describes as the Battle of Donbas, a campaign to seize two provinces and salvage a battlefield victory. 

* April 21: Putin declares Mariupol "liberated" after nearly two months of siege.

* April 28: Russia fires two missiles into Kyiv during a visit by U.N. Secretary-General Antonio Guterres, Ukraine says.

* May 1: About 100 Ukrainian civilians are evacuated from Mariupol‍‍`s ruined Azovstal steelworks.

* May 7: As many as 60 people are feared dead after a bomb strikes a village school in Bilohorivka, eastern Ukraine.

* May 10: Ukraine says its forces have recaptured villages from Russia north and northeast of Kharkiv, pressing a counter-offensive that could signal a shift in the war‍‍`s momentum and jeopardise Russia‍‍`s main advance. 

* May 12: More than 6 million people have fled Ukraine, the UNHCR says.

* May 13: Video from Ukraine‍‍`s military appears to show Ukrainian forces destroying parts of a Russian armoured column as it tries to cross the Siverskyi Donets river in the eastern Donbas region. Reuters cannot verify the footage.