U.S. President Barack Obama says the U.S. is leading the world in opposing Russia's aggression against Ukraine.
Speaking Saturday in Australia at the University of Queensland in Brisbane, Mr. Obama said Russia is "a threat to the world" as witnessed in the "appalling shoot-down of MH17;" a reference to the downing of Malaysia Airlines Flight 17 in July as it flew through rebel-held territory in Ukraine en route from Amsterdam to Kuala Lumpur.
"As the world's only super power, the United States has unique responsibilities that we gladly embrace," said Obama. "We're leading the international community in the fight to destroy the terrorist group ISIL (Islamic State), we're leading in dealing with Ebola in West Africa and in opposing Russia's aggression against Ukraine...a tragedy that took so many innocent lives, among them your fellow citizens."
Ukrainian President Petro Poroshenko says the situation in eastern Ukraine must be resolved through dialogue with the Russian-backed separatists. However, Poroshenko said Friday the Ukrainian military is "willing and able to fight back" if the cease-fire collapses completely.
Putin wants compromise
Russian President Vladimir Putin has said he wants to reach a compromise with Ukraine, but the Kremlin denies having any soldiers or weapons in rebel-controlled areas.
Ukraine's prime minister, Arseniy Yatsenyuk, says building an army strong enough to stop Russian aggression is the country's number one task.
NATO and European observers report seeing Russian tanks, troops and weapons crossing the border into eastern Ukraine this past week. A cease-fire declared in September has been violated consistently almost since the day it was signed.
Moscow says it is Ukraine that is massing forces along the front lines, ignoring an agreement to pull them back.
Obama and Putin are both in Brisbane, attending the summit of the Group of 20 economic powers.
U.S. Secretary of State John Kerry has called for the immediate implementation of the cease-fire and securing and monitoring of the Ukraine-Russia border.
As world leaders gathered in Australia for the summit, Russian President Putin, in an interview Friday with Russia's official Tass news agency, complained about U.S.-led sanctions against Russia for its military activity in Ukraine. He said Washington is "crudely violating" the spirit of international cooperation.
EU considers sanctions
European Union President Herman von Rompuy says European foreign ministers will meet Monday after the summit to assess the situation in Ukraine and talk about "possible further steps," which could mean more sanctions against Moscow.
EU leaders also plan to discuss Ukraine with U.S. President Barack Obama on the sidelines of the summit.
Australia has sent its fleet into international waters to monitor the activity of four Russian warships that arrived off the country's northeast coast.
Russian authorities say their naval maneuvers and air force flights over the Gulf of Mexico and Caribbean are only routine training missions to test the range of Russian military equipment. But Australian Prime Minister Tony Abbott accuses Putin of trying to "revive the lost glories of tsarism."
