Ukraine said it plans to reinforce its eastern border with Russia and withdraw troops from Crimea, ceding control of the Black Sea peninsula as tensions remained high over Russian moves to annex the breakaway region.

Demilitarizing Crimea “is the best way to de-escalate the situation,” Andriy Parubiy, head of Ukraine’s National Security Council, told reporters in Kiev yesterday. He declined to say when forces would leave, and his announcement came as pro- Russian civilians overran bases in the region and temporarily detained Ukrainian personnel, including its navy chief.

Russian President Vladimir Putin’s takeover of Crimea has set off the worst confrontation in two decades with the West, which is struggling to respond. European Union leaders meet today to try to formulate a unified position on punishing Russia. North Atlantic Treaty Organization Secretary General Anders Fogh Rasmussen yesterday described the standoff as “a wake-up call” for the international community

“This is the gravest threat to European security and stability since the end of the Cold War,” Rasmussen said at an event in Washington. “The only way to address such challenges is for Europe and North America to stand together.”

Ukraine’s move to fortify its eastern border highlights concerns in Kiev that Russia may try to create turmoil in areas with large pro-Russia populations. The governor of the eastern Kharkiv region warned this week that Russia had massed forces along roadways about 15 kilometers (9 miles) from the frontier.

Personnel Released

“It’s crystal clear for us that Russian authorities will try to move further and escalate the situation in southern and eastern Ukraine,” interim Ukrainian Prime Minister Arseniy Yatsenyuk said in an interview early today in Brussels. “But we still maintain control and we still preserve the fragile stability in these regions.”

Pro-Russian groups in Crimea released Ukrainian military personnel today after seizing installations in the region, home to Russia’s Black Sea Fleet. The government in Kiev said yesterday it would bolster security at nuclear installations, pursue compensation from Russia for seized assets and withdraw from the Commonwealth of Independent States, a regional organization composed of former members of the Soviet Union.

‘Ukrainian Territory’

Yatsenyuk dismissed the March 16 Crimean vote to join Russia. “Crimea is a Ukrainian territory,” he said. “No one will recognize this so-called referendum and annexation.”

In a March 18 speech to lawmakers, Putin blamed Western encroachment for forcing him to take control of Crimea. While he said Russia doesn’t plan to further split up Ukraine, he asserted his right to defend Russian speakers in Ukraine’s east.

Putin’s approval rating has surged 11.4 points in the last month to a five-year high of 75.7 percent, primarily because of events in Ukraine, state-run polling company VTsIOM said today in an e-mailed statement. The survey of 1,600 people in 42 Russian regions had a margin of error of 3.4 percentage points.

Russia will continue to use political, diplomatic and legal methods to protect its citizens abroad, the Ria Novosti news service reported, citing Foreign Minister Sergei Lavrov.

Even with the standoff over Crimea, Ukraine will meet payments on the $3 billion of Eurobonds it sold to Russia three months before Putin’s military incursion into the Black Sea region, a Finance Ministry official in Kiev said yesterday.

Debt Pledge

“Ukraine will pay its debts as it has been doing before,” said Denis Khristoforov, an official in the ministry’s sovereign-debt department. “If we do not pay, it will mean de- facto a default. Ukraine doesn’t want that.”

Ukraine’s new government is seeking as much as $15 billion in international support to help it stave off default. The EU, the U.S. and the International Monetary Fund are developing assistance packages to shore up Ukraine’s economy.

EU leaders meet today in Brussels to try to overcome differences on how to pressure Putin into a retreat after Russian officials shrugged off an earlier round of visa bans and asset freezes by the EU and U.S. While British Prime Minister David Cameron vowed to push European heads of state to agree on additional measures, others were less sure.

The summit probably won’t agree on economic sanctions, Czech Prime Minister Bohuslav Sobotka said yesterday, the CTK news service reported. Penalties against Russia should be gradual and reversible so as to avoid a return to the “Iron Curtain,” Italian Prime Minister Matteo Renzi told lawmakers.

No War

President Barack Obama said yesterday the U.S. won’t take military action to confront Russia in Ukraine and is instead relying on international pressure on Putin’s government.

The U.S. and Europe will be working on more measures over the next several days that, if the current standoff continues, “could end up having a significant impact on the Russian economy,” Obama said in an interview with St. Louis television station KSDK recorded at the White House.

“We do not need to trigger an actual war with Russia,” the president said. “Nobody would want that.”

U.S. Vice President Joe Biden yesterday wrapped up a two- day trip to Poland and Lithuania, both NATO members on the front lines of the Ukrainian confrontation. In meetings with regional leaders, he sought to assure them of U.S. support if Russia made any attempt to encroach on their territory.

United Nations Secretary-General Ban Ki-moon was headed last night to Moscow for a meeting there today with Putin and Lavrov. Ban will travel to Kiev tomorrow to meet Turchynov, Yatsenyuk and members of the UN’s human-rights monitoring mission to Ukraine.

Some of the 34 UN observers — 9 international and 25 national staff — will start monitoring in Kharkiv and Donetsk tomorrow to independently assess allegations of rights violations, UN Assistant-Secretary-General for Human Rights Ivan Simonovic told the Security Council yesterday in New York.

There are allegations of torture, arbitrary arrest, detention and ill-treatment in Crimea, while reports of rights violations in Ukraine appear to be “neither widespread nor systemic,” Simonovic said.