Follow the latest in Ukraine live

All updates in Universal Coordinated Time (UTC)

22:00: UN Secretary-General Ban Ki-moon has ruled out deploying UN peacekeepers to stabilize the situation in eastern Ukraine. Ban said the idea wasn't practical. Peacekeepers would require a mandate from the UN Security Council, where Russia holds a veto. Ukraine's interim president had floated the idea of peacekeepers before Kyiv launched an operation against separatists in Ukraine's east on Tuesday.

21:54: The US State Department has said that Washington is unlikely to impose additional sanctions against Moscow before a Thursday meeting in Geneva of envoys from the US, EU, Russia and Ukraine.

19:59 - Russian Foreign Ministry spokesman Aleksandr Lukashevich, in his response to the UNHCR paper on the situation in eastern Ukraine, is particularly critical about February's change of government in Kyiv: "The authors of the report chose not to notice that the current 'authorities' in Ukraine have become such as a result of an armed coup d'etat." Lukashevich laments that "not a word" of the UN report addressed the February 22 ouster of President Viktor Yanukovych. Full story, via Voice of Russia and the Foreign Ministry here:

19:26 - British Foreign Secretary William Hague said Russia has deliberately pushed Ukraine "to the brink" in recent days and increased the risk of violent confrontation there. Parts of Hague's speech at a mayoral banquet in London were released by the British Foreign Office (@foreignoffice) in advance on Twitter, including:

19:14 - German Chancellor Angela Merkel and Russian President Vladimir Putin have spoken on the phone amid the fighting in Kramatorsk. According to a German government spokeswoman, quoted by the Reuters news agency in German, the two leaders "evaluated the most recent events differently." Merkel and Putin can both fluently speak each other's native tongues. On Monday, Merkel had issued one of her more critical comments concerning alleged Russian involvement in the unrest in Ukraine. Merkel's spokeswoman said that "many things indicate that the armed groups in the east of Ukraine are receiving support from Russia."

18:12 - In an interview with weekly paper Die Zeit, German Foreign Minister Frank-Walter Steinmeier has said it "would be good if Russia were to distance itself from the violent and illegal actions of pro-Russian demonstrators."

17:55 - The UN has acknowledged the phone conversation between Secretary-General Ban and Russian President Putin on Twitter, saying Ban stressed "the need for everyone to work to de-escalate the situation."

17:47 - The Pentagon confirmed on Tuesday that Russia had carried out a routine test-launch of an intercontinental ballistic missile (ICBM) on Monday. "The launch was a previously notified and routine test launch of an ICBM. Notifications were conducted as required under the new START treaty," Pentagon spokesman Colonel Steven Warren said. Such tests are comparitively routine and regular; Russia last test-fired an ICBM on March 4.

17:45 - Russian President Vladimir Putin has called for the UN and international community to condemn the Ukrainian operations in a phone call with Ban Ki-moon. According to a statement from the Kremlin, Putin "underscored that the Russian side expects a clear condemnation from the United Nations and the international community of these anti-constitutional actions."

17:15 - In Washington, White House spokesman Jay Carney has described Ukraine's response to an "untenable" situation in the east as "measured." Despite urging "all due caution" in any security service operations, Carney said the interim government in Kyiv had a "responsibility" to safeguard law and order.

17:11- In other Tuesday developments, German energy company RWE has said it will start providing gas to Ukraine - a key transit country heavily dependent on Russia for its energy. The unrest has also weighed heavily on Germany's monthly ZEW investor confidence index, published today, which slid 3.4 points month-on-month.

17:06- The Russian Foreign Ministry has criticized the UN's human rights report (see 16:46 entry), calling it "one-sided, politicized and not objective." The ministry said in a statement that "one gets the impression that the report was fabricated to correspond with conclusions formed in advance." Foreign Minister Sergei Lavrov said earlier on Tuesday that the military action in Ukraine could endanger four-way talks in Geneva - between Russia, Ukraine, the US and the EU - due to start on Thursday.

16:46 - Russian Prime Minister Dmitry Medvedev responded to the intervention in Kramatorsk by saying that "Ukraine is on the brink of civil war - it's frightening." Moscow has repeatedly said it is concerned for ethnic Russians in eastern Ukraine since the country's change in government. The UN, however, questioned this assertion in a report released on Tuesday. "Although there were some attacks against the ethnic Russian community, these were neither systematic nor widespread," the UN's human rights office surmised.

16:41- Ukrainian troops have secured a military airfield near Kramatorsk, just south of the rebel stronghold of Slavyansk. The town is roughly 160 kilometers (100 miles) from the Russian border. Witness reports suggest that the base is now being used to shuttle in more security forces by helicopter. A soldier who gave only his first name, Taras, to the Associated Press said: "We are awaiting the order to move on Slovyansk."

16:30 - Interim President Oleksander Turchynov told parliamentarians in Kyiv on Tuesday that the country's attempts to regain control of several towns and cities in the east of the country had begun: "The anti-terrorist operation began during the night in the north of Donetsk region. But it will take place in stages, responsibly, in a considered way. I once again stress: the aim of these operations is to defend the citizens of Ukraine."

msh/dr (AFP, AP, dpa, Reuters)