BRUSSELS (AFP) - US President Barack Obama announced a new round of punitive measures for Moscow's annexation of Crimea on Thursday as Europe's leaders also readied to hit back at Russia with fresh sanctions.
But in Moscow, where the lower house of parliament rubber-stamped the absorption of the rebel peninsula, Russia issued its own list of sanctions against nine US officials, including senior political figures and presidential aides.
Mr Obama, who threatened to target the broader Russian economy if Moscow does not reverse course, said: "Russia must know that further escalation will only isolate it further from the international community." The latest US measures in the worst East-West crisis since the Cold War target a new list of 20 lawmakers and senior government officials in addition to 11 people already sanctioned by Washington.
Among those named are top businessmen close to President Vladimir Putin such as billionaires Gennady Timchenko, Arkady Rotenberg and Boris Rotenberg plus a bank used by close associates.
In turn, Moscow listed Obama aides Caroline Atkinson, Daniel Pfeiffer and Benjamin Rhodes and senators Mary Landrieu, John McCain and Daniel Coats.
"There should be no doubt: each hostile attack will be met in an adequate manner," the Russian foreign ministry said, while Putin's spokesman slammed Mr Obama's move as "unacceptable."
In Brussels, where the 28-nation European Union was gathering for its second summit on Ukraine in less than two weeks, French President Francois Hollande said: "Borders cannot be redrawn and a region allowed to pass from one nation to another without a response."
Mr Hollande said the bloc's leaders would announce fresh sanctions at the two-day meeting "against a certain number of figures" and would cancel an EU-Russia summit planned for June.
The EU sanctions target at least 12 individuals, "all of them Russian," and all highly-placed, including advisers to Putin "but there are no government ministers" among them, said a diplomat speaking on condition of anonymity.
The list includes Deputy Prime Minister Dmitry Rogozin, who heads Russia's Military-Industrial Commission and is among those targeted by the United States.
But EU nations, heavily dependent on Russian oil and gas, are divided on how far they should go, with many reluctant to take the next step up with tough economic sanctions.
"We will make clear that we are ready in case of further escalation to introduce economic sanctions," said German Chancellor Angela Merkel, whose country is Russia's leading EU trading partner.
Kiev interim premier Arseniy Yatsenyuk will be in Brussels to sign the political parts Friday of a broad EU Association Agreement whose rejection in November by Ukraine's pro-Kremlin president Viktor Yanukovych sparked the protests that led to his fall.
Mr Putin meanwhile found himself on the defensive in Moscow when United Nations Secretary-General Ban Ki-moon told him: "I cannot but to tell you that I am deeply concerned." Mr Ban called for the deployment to Ukraine of rights monitors from the UN and the Organisation for Security and Co-operation in Europe (OSCE) and for an "honest and constructive dialogue" between Moscow and Kiev.
Sanctions and calls for talks have so far done nothing to halt Russian military advances, with Kiev's new Western-backed government preparing a Crimean evacuation plan for thousands of Ukrainian soldiers and their families.
Tensions eased somewhat in the region when acting president Oleksandr Turchynov announced the release Thursday by Crimean militias of Ukranian navy chief Sergiy Gayduk.
Mr Turchynov had threatened the Crimean authorities with "an adequate response ... of a technical and technological nature" unless they freed Gayduk and several others who were captured during the storming of Ukraine's naval headquarters in the port of Sevastopol on Wednesday.
But Ukraine's defence ministry on Thursday said around 20 gunmen seized a Ukrainian warship, the Ternopil, in the port of Sevastopol in Crimea.
