Ukraine's Poroshenko had earlier claimed in a tweet that a cease-fire was reached in a part of eastern Ukraine, but Russia refuted the claim.
Australia, which will host a G20 summit in November, has said that opposition to Vladimir Putin's presence at the meeting is growing.
Russia denies its troops are involved in fighting on the ground, in the face of what Western countries and Ukraine say is overwhelming evidence.
Vladimir Putin's claims that he could take Kiev in two weeks have been taken out of context, says the Russian president's advisers.
NATO had, on Monday, announced plans to form a "very high readiness force" to respond to Russian aggression in Ukraine.
Putin made the boast as European leaders considered more sanctions against Russia for its actions in Ukraine.
Russia and China launched construction of an almost-2,500-mile natural-gas pipeline between themselves Monday.
Poroshenko said in a speech there would be high-level personnel changes in the Ukrainian armed forces.
The fresh set of bans from Australia will affect 63 Russian and Ukrainian individuals, along with 21 corporations.
Rep. Peter King says Putin has to know there's "a price to pay" for his actions in Ukraine.
The troop exchange occurs as Ukraine accuses Russia of providing pro-Russian separatists with soldiers and armored vehicles.
Ukraine and pro-Russian separatists should discuss "issues of society's political organization and statehood," Vladimir Putin says.
Polish Prime Minister Donald Tusk was appointed Saturday to be the EU's primary representative on the world stage.
Van Rompuy says new sanctions against Russia will be drawn up within a week.
Ukraine President Petro Poroshenko solicited EU support Saturday during discussions of his country's conflict with pro-Russian separatists.
"I want to remind you that Russia is one of the most powerful nuclear nations. This is a reality," the Russian president said Friday.
After more than 20 years as an independent country, Ukraine looks to join NATO. Other ex-Soviet nations already have.
The separatists say they will allow civilians and government troops who lay dow their arms to leave, following a request from Vladimir Putin.
Russian hackers are believed to have hacked JPMorgan Chase and stolen a trove of executives' "sensitive documents."
The currency switch is a protective measure for Russia, since U.S. dollars can be tracked and controlled by American officials.
Ukrainian President Petro Poroshenko has confirmed that Russia has breached its borders and hinted at a possible international response.
Russia has denied Ukraine's claims and said that it's not involved in “Ukraine hostilities.”