A Russian troop buildup at Ukraine’s border threatens to intensify a long-running conflict.The US and its allies, including Ukraine, are trying to forestall that scenario, most recently in a two-hour video call Tuesday between President Joe Biden and Russian President Vladimir Putin.
Here are the latest developments in the war in Ukraine:
Ukraine says it is pausing the evacuation of civilians from the war-scarred east of the country for a day because of a failure to agree terms with Russian forces.
"As of this morning, April 17, we have not been able to agree with the occupiers on a ceasefire on the evacuation routes. That is why, unfortunately, we are not opening humanitarian corridors today," Ukrainian Deputy Prime Minister Iryna Vereshchuk stated.
How will Russia attack Ukraine's new front line?
Artillery may decide the key battles looming in Donetsk and Luhansk, say military analysts.Analysts believe Ukraine's best units are in the east, and that they are dug into trench systems and other fortified positions.
- Military plant hit: Russia -
Russia's defence ministry says it has struck a military plant outside Kyiv, as Moscow intensifies its attacks on the Ukrainian capital.
"During the night, high-precision, air-launched missiles destroyed an ammunitions factory near the settlement of Brovary, Kyiv region," the ministry said in a statement on Telegram.
- 'Inhuman' situation in Mariupol -
Ukrainian President Volodymyr Zelensky says the situation in the eastern city of Mariupol is "inhuman", warning the "elimination" of the last Ukrainian troops defending would end peace talks with Russia.
"Russia is deliberately trying to destroy everyone who is there," he says in a video address.
- Russian ultimatum -
Russia's defence ministry says it has cleared the whole of Mariupol's "urban area" of Ukrainian forces.
Civilians urged to flee eastern Ukraine as Zelenskyy warns of 'hard battle' to come
Video: Russia is likely to increase its attacks in Ukraine (MSNBC)
They say the only remaining Ukrainian soldiers are in the Azovstal metalworks -- and that their only chance to live is to "lay down their arms and surrender".
- 'Useless' talking to Putin: Draghi -
Italian Prime Minister Mario Draghi has complained in a newspaper interview that Western diplomatic efforts to persuade Vladimir Putin to halt the war in Ukraine had so far led nowhere.
"I am beginning to think that those people are right when they say 'It is useless to talk to him, it's just a waste of time'," Draghi told the daily Il Corriere della Sera, adding Putin's goal appeared not peace but "to annihilate the Ukrainian resistance, occupy the country and entrust it to a friendly government."
- Sanctions and reprisals -
Amid escalating tit-for-tat sanctions, Russia bans entry to British Prime Minister Boris Johnson and several of his senior ministers.
How real is the threat of a Russian invasion of Ukraine?
Experts are divided on whether Moscow is planning an imminent incursion, or merely posturing to win geopolitical sway.Russian President Vladimir Putin wants his troops to reach the Dnieper River that dissects Ukraine, seize a land corridor to annexed Crimea and ensure the resumption of water supply to the arid peninsula that was cut off in 2014 causing a chronic drought, said Ihor Romanenko, a retired lieutenant general and Ukraine’s former deputy chief of staff.
The Kremlin also steps up a crackdown on dissent at home, adding nine prominent Kremlin critics and journalists to its growing list of "foreign agents".
A Russian court orders the pre-trial jailing of a Siberian news editor for alleging that 11 riot police refused to join the military campaign in Ukraine.
- Three killed in de-mining operation -
Three sappers have been killed and four wounded while trying to clear mines near the eastern city of Kharkiv, Ukraine's interior minister Denys Monastyrsky says.
- Russia says shot down arms shipment -
Russia's defence ministry claims to have shot down a Ukrainian transport plane carrying weapons supplied by western countries in the Odessa region.
- No homes to return to: UN -
Many of the nearly five million people who have fled Ukraine will not have homes to return to, the United Nations warns.
UNHCR, the UN refugee agency, says 4,836,445 million Ukrainians have left the country since the Russian invasion on February 24 -- up 40,200 on Friday's total.
The weapons being sent to Ukraine and why they may not be enough .
The arms Ukraine receives will be vital to the outcome of the war, but will it get the influx of heavy weapons it needs?However, Ukrainian resistance was much stronger than anticipated and Russian armoured columns were not only halted but in many cases destroyed as Ukraine leveraged what weapons it had to the greatest effect, its commitment to defend itself with great energy, surprising Russia and the world. Since then, Ukraine has seen a flood of arms as weapons pour in from Europe and the United States.