We are now closing our live blog for today. Don't forget that you can keep up with all our ongoing Ukraine coverage here.
Here are some more details from our news desk on Obama's comments in Washington:
U.S. President Barack Obama says the "ongoing incursion" into Ukraine by Russia will only lead to additional costs for Moscow.
The U.S. leader said Russia is training, arming and funding pro-Russian separatists in Ukraine.
Obama says new images of Russian forces inside Ukraine make that plain to see.
But he said "we are not taking military action to solve the Ukrainian problem."
Obama also said Ukraine President Petro Poroshenko will visit the White House next month.
Obama was speaking to reporters in Washington today shortly after an emergency session at the UN Security Council on the crisis in Ukraine.
U.S. Ambassador Samantha Power said Russia must "stop lying" about its invasion of eastern Ukraine and its direct military support for pro-Kremlin separatists there.
Ukrainian officials say two Russian military columns have rolled into the southeastern part of Ukraine after missiles were fired at a border post.
(AP, Reuters)
!!! BREAKING NEWS !!!
U.S. President Barack Obama is briefing the press in Washington. He says the "ongoing incursion" into Ukraine by Russia will only lead to additional costs for Moscow. Obama said sanctions imposed so far have hurt Russia. He also said Ukrainian President Petro Poroshenko will visit the White House next month.
1/4 A couple of things to think about. Russia's economy can't sustain a long war and a long protracted market fluctuations, no investment.
— Ben Judah (@b_judah) August 28, 2014
2/4 So, if you are thinking fiscally, which they are likely not, its best to get whatever you want to do over quickly and weather the storm.
— Ben Judah (@b_judah) August 28, 2014
3/4 The potential for an anti-war movement in Russia is much, much, much bigger than the liberal protests of 2011. Especially as people die.
— Ben Judah (@b_judah) August 28, 2014
4/4 And, despite sanctions, doom headlines, oil authoritarians can keep going for decades even if they are blockaded from West. Think Iran.
— Ben Judah (@b_judah) August 28, 2014
The UN Security Council meeting on Ukraine is under way and the United States' Susan Power has had some harsh words for Moscow:
U.S. Ambassador Samantha Power told an emergency session of the UN Security Council on August 28 that Russia must "stop lying" about its invasion of eastern Ukraine and its direct military support for pro-Kremlin separatists there.
Power told the UN Security Council that Washington will continue working with its partners from the Group of Seven leading industrialized nations "to ratchet up consequences on Russia.”
Saying that Russia's "mask is beginning to come off," Power said that the Kremlin's "blatant disregard for the United Nations Charter will not be tolerated."
She told the Security Council: "Now, the key question to be answered is not what we can say to Russia to make them hear us, but what we can do."
Urging strong international action against Moscow, Power said that in the face of the threat now posed by Russia, "the cost of inaction is unacceptable."
Hmm, it seems that Canadian tweet has raised some Russian hackles (and incidentally isn't Moscow supposed to have recognized Abkhazia as a state...?):
Helping our Canadian colleagues to catch up with contemporary geography of #Europe @CanadaNATO pic.twitter.com/MjzRxpFFfN
— Russians at NATO (@natomission_ru) August 28, 2014