NATO and Russia have agreed to meet Wednesday for talks on the crisis in Ukraine. That meeting, in Brussels, will be the first public contact between the Western defense alliance and Russia's envoys since its forces moved into Ukraine's Crimean peninsula late last week.
NATO announced the extraordinary session Tuesday, saying it was requested by Secretary-General Anders Fogh Rasmussen. The alliance offered no further details.
Members of NATO met earlier Tuesday at the request of Poland, which shares a border with Ukraine. Afterward, the alliance said the Russian military presence in Ukraine presents "serious implications for the security and stability of the Euro-Atlantic area."
Meanwhile in Paris, U.S. Secretary of State John Kerry is expected to meet Wednesday with Russian Foreign Minister Sergei Lavrov.
Obama calls for direct Moscow-Kyiv talks
U.S. President Barack Obama Tuesday called on Russia to open talks with the Ukraine’s interim government, and to allow international monitors to determine whether ethnic Russians in Ukraine are under threat, as alleged by Moscow.
Obama spoke in Washington, following a news conference in Moscow by Russian President Vladimir Putin. The Russian leader defended his country's military intervention in the Crimean peninsula last week, saying he reserves the right to protect Russians in Ukraine. But he also insisted that gunmen blocking Ukrainian military units in the region are "local self-defense forces," not Russian soldiers.
President Obama countered that Moscow has no legal right to intervene militarily, while acknowledging that Putin "seems to have a different set of lawyers making a different set of interpretations."
Late Tuesday, in a sign interpreted cautiously by analysts, NATO said Russia has agreed to attend an emergency NATO-Russia council meeting in Brussels Wednesday to discuss the crisis.
Kerry condemns Russian 'aggression'
U.S. Secretary of State John Kerry says the United States would prefer to de-escalate tensions with Russia over Ukraine.
During a visit to Kyiv Tuesday, Kerry met Ukraine's interim leaders and announced a $1 billion economic package and technical assistance for the new government.
He also condemned the presence of Russian troops in Crimea as an "act of aggression."
Meeting with reporters while in Kyiv, Kerry said diplomacy and respect for sovereignty, not unilateral force, can best resolve the dispute over Ukraine.
“We are not seeking confrontation," he said. "There is a better way for Russia to pursue its legitimate interests in Ukraine.”
Kerry said if Russia does not choose to de-escalate the situation through diplomatic means, the U.S. and its partners will have no choice but to isolate Russia politically and economically.
European Union foreign ministers have issued a Thursday deadline for Russian President Vladimir Putin to pull back his troops or face punitive measures.
The Russian Foreign Ministry warned that Moscow would retaliate against any sanctions.
'Moving' visit
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U.S. Secretary of State John Kerry, right, shakes hands with a Ukrainian protester at the barricades in Kyiv, Ukraine, March, 4, 2014.
During his one-day visit, Kerry met enthusiastic crowds at Independence Square, where some protesters chanted "thank you" to America's top diplomat, who also placed flowers at a memorial to fallen protesters.
Kerry said he was moved by his visit to Independence Square, noting the bullet holes, barricades and barbed wire he saw there.
He praised "brave Ukranians who stood against tyranny" asking for the right to define their own future.
“It is universal, it is unmistakable, this call for freedom,” Kerry said. “In this transformation, we will stand with the people of Ukraine.”
Russia considers 'all options'
Earlier Tuesday, Putin said he would use force in Ukraine only as a last resort.
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In this frame grab provided by the Russian Television via the APTN, President Vladimir Putin, during a live feed, answers journalists' questions on the current situation around Ukraine, March 4, 2014.
In his first public comments since the crisis began, Putin said there had been an unconstitutional coup in Ukraine and that ousted President Viktor Yanukovych was still the legitimate leader.
"As for bringing in forces. For now there is no such need but such a possibility exists,'' Putin said, looking relaxed as he sat before a small group of reporters at his residence near Moscow. "It would naturally be the last resort, absolutely the last."'
But tension remained high on the ground. Reuters reported that Russian forces fired warning shots in a confrontation with Ukrainian servicemen at an air base, and Russian navy ships were reported to have blockaded the strait separating the Ukrainian Black Sea peninsula from Russia.
Also Tuesday, Russia said it had successfully test-fired an Intercontinental Ballistic Missile (ICBM) which was launched about 450 km east of the Ukrainian border. A U.S. official said the United States had received notification from Russia ahead of the test and that the initial notification pre-dated the crisis in Crimea.
WATCH: RFE/RL video of Pro-Russian Troops in Simferopol, Crimea
Meantime, Ukraine said on Tuesday that observers from a pan-European security body would travel at its invitation to the Crimea region, where Russian forces have taken control, in an attempt to defuse a military standoff, Reuters reported.
It was not immediately clear whether Russia would allow monitors to enter the region, where it controls the airspace and access points. Diplomatic sources told Reuters Russia's agreement was not legally necessary.
Elsewhere, Putin ordered tens of thousands of troops taking part in military exercises in western Russia, near the Ukrainian border, to return to base. The exercises were scheduled to end, so it is unclear whether the move was intended to help ease tensions.
Telecommunications 'attack,' protecting nuclear power
The head of Ukraine's security service said the country's telecommunications system has come under attack. Valentyn Nalivaichenko said equipment installed in Russian-controlled Crimea was used to interfere with the mobile phones of members of parliament, Reuters reported Tuesday.
Some Internet and telephone services were interrupted after Russian forces seized control of airfields and key installations in Ukraine's Crimea region Friday, but now lawmakers were being targeted, Nalivaichenko told a news briefing.
"I confirm that an...attack is under way on mobile phones of members of Ukrainian parliament for the second day in row,'' he said.
Reuters reported that Ukraine is also reinforcing security at its 15 nuclear power plants because of "a grave threat to the security" of the country posed by the Russian military, it told the U.N. atomic watchdog on Tuesday.
Crimea is a Black Sea peninsula placed under Ukrainian control in 1954 by then-Soviet leader Nikita Khrushchev. It remained part of Ukraine when the Soviet Union collapsed in 1991.
Crimea has a tiny border with Russia on its far eastern point, and the Crimean port of Sevastapol is home to Russia's Black Sea fleet. Most of the people living in Crimea are ethnic Russians, but the region also is home to ethnic Muslim Tatars, who generally show disdain for Russia.
Ukraine's troubles began in November, when President Yanukovych backed out of a trade deal with the European Union in favor of closer ties and economic aid from Russia. The move triggered weeks of pro-Western anti-government demonstrations in Kyiv and elsewhere in Ukraine, and forced the pro-Russian Yanukovych to flee the capital in late February.
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