President Barack Obama on Thursday increased pressure on Russia over its annexation of Ukraine's Crimean peninsula, announcing additional economic sanctions against Moscow that will hit 20 Russian officials and a bank that provides them with support.
The sanctions are the latest in a wave of political and economic actions against Russia by the United States and the European Union after Russia moved to annex Crimea.
Obama also signed an executive order authorizing more severe sanctions that would affect "key sectors of the Russian economy" if necessary, though he noted the escalated sanctions could have a profound impact on the global economy.
The president said the penalties were the result of "choices the Russian government has made, choices that have been rejected by the international community."
The sanctions are the second wave of penalties the U.S. has levied on Russia this week, following economic sanctions ordered Monday on 11 people the U.S. said were involved in the dispute in Ukraine.
Moments after Obama's announcement Thursday, Russia issued its own wave of sanctions against U.S. officials, including deputy national security adviser Benjamin Rhodes; Sens. John McCain, R-Ariz., Harry Reid, D-Nev., and Mary Landrieu, D-La.; and House Speaker John Boehner, R-Ohio.
Russia’s sanctions restrict travel for the U.S. lawmakers and officials. The Russian Foreign Ministry also issued a statement indicating that it will retaliate to each round of U.S. sanctions.
"There will be no doubt: we will respond adequately to every hostile thrust," the ministry said in a statement.
The move comes as Russia faces further sanctions from the European Union on Thursday over the annexation.
In an address to the German parliament in Berlin, Chancellor Angela Merkel said the EU was readying further sanctions and that the G-8 forum of leading economies had been suspended indefinitely.
Russia holds the presidency of the G-8, and President Vladimir Putin was due to host his counterparts, including Obama, at a summit in Sochi in June.
"So long as there aren't the political circumstances, like now, for an important format like the G-8, then there is no G-8," Merkel said. "Neither the summit nor the format."
Moscow formally annexed Crimea earlier this week. The Black Sea peninsula had been part of Russia for centuries until 1954, when Soviet leader Nikita Khrushchev transferred it to Ukraine.
On Thursday Russia's 450-member State Duma, the lower house of parliament, approved the treaty signed by Putin and leaders of Crimea that makes the territory a part of Russia.
The treaty must still be approved by the 166-member Federation Council, the upper house, before Crimea is officially a part of Russia.
Russian forces effectively took control of Crimea some two weeks ago after the ouster of Ukraine's pro-Russia president, Viktor Yanukovich, following months of protests and sporadic violence.
The crisis erupted late last year after Yanukovich backed out of an association deal with the EU in favor of a promised $15 billion bailout from Russia. That angered Ukrainians from pro-European central and western regions.
Merkel said EU leaders would increase those "level two" sanctions against Russia when they meet later Thursday in Brussels to widen the list of those whose assets are being frozen and who are banned from traveling.
She also reiterated that if things worsen, the EU is prepared to move to "level three" measures, which would include economic sanctions.
"The European Council will make it clear today and tomorrow that with a further deterioration of the situation we are always prepared to take level three measures, and those will without a doubt include economic sanctions," she said.
Merkel's tough approach came as the commander of Ukraine's navy was freed after being held by Russian forces and local Crimean militia members at the navy's headquarters.
Rear Adm. Sergei Haiduk and an unspecified number of civilians were held for hours after the navy's base in Sevastopol was stormed Wednesday. Early reports said the storming was conducted by a self-described local defense force, but Thursday's statement by acting President Oleksandr Turchynov, which confirmed the release, said Russian forces were involved.
Just how many retreating troops Ukraine will have to absorb in what amounts to a military surrender of Crimea was unclear. Many servicemen have already switched sides to Russia, but authorities said they were prepared to relocate as many as 25,000 soldiers and their families to the Ukrainian mainland.
With thousands of Ukrainian soldiers and sailors trapped on military bases, surrounded by heavily armed Russian forces and pro-Russia militias, the Kiev government said it was drawing up plans to evacuate its outnumbered troops from Crimea back to the mainland and would seek United Nations support to turn the peninsula into a demilitarized zone.
U.N. Secretary-General Ban Ki-moon met with Putin, Foreign Minister Sergey Lavrov and other senior Kremlin officials on Thursday and expressed his concern over the continued escalations in the region.
"I am seriously concerned that developments in Ukraine and the increasing tensions between Ukraine and Russia pose grave risks to the countries themselves, the region and beyond," Ban said. "It is clear that that we are at a crossroad. We must employ every possible diplomatic tool at our disposal to solve this crisis, which has grave political and economic ramifications."
On Friday the secretary-general travels to Kiev, where he will hold talks with Turchynov, Prime Minister Arseniy Yatsenyuk and others to discuss the ongoing crisis in the region.
"We are working out a plan of action so that we can transfer not just servicemen but, first of all, members of their family who are in Crimea quickly and effectively to mainland Ukraine," said Andriy Parubiy, secretary of Ukraine's National Security and Defense Council.
Since the Russian forces took charge in Crimea, Ukrainian-enlisted personnel and officers have been bottled up in barracks and other buildings at one end of the Belbek air force base, with the Russians in control of the airfield.
"We're waiting for what Kiev, our leadership, tells us," said one major, who declined to give his name. The major said he expected about half of the personnel still at the base to accept the Russian offer to stay and join the Russian armed forces, since they are Crimea natives.
Humbled but defiant, Ukraine lashed out symbolically at Russia by declaring its intent to leave the Moscow-dominated Commonwealth of Independent States, a loose alliance of 11 former Soviet nations.
The last nation to leave the group was Georgia, which fought a brief war with neighboring Russia in 2008 and ended up losing two separatist territories.
Al Jazeera and wire services