U.S. President Barack Obama has said the United States and Europe are united in holding Russia to account for its actions in Crimea.
"Europe and America are united in our support of the Ukrainian government and the Ukrainian people," he told reporters after meeting with Dutch Prime Minister Mark Rutte in Amsterdam on March 24. "We are united in imposing a cost on Russia for its actions so far."
Obama told the Dutch newspaper "de Volkskrant" that his message to European leaders is that Russian President Vladimir Putin needs to "understand the economic and political consequences of his actions in Ukraine" but that "it's important that Ukraine have good relations with the United States, Russia, and Europe."
He called Europe Washington's closest partner on the world stage and said Europe is the cornerstone of American engagement with the world.
Obama will travel later on March 24 to The Hague for talks with Chinese President Xi Jinping and to attend a Nuclear Security Summit.
He is then due to sit down in a meeting with other leaders from the Group of Seven (G7) leading industrial nations -- Germany, France, Canada, Italy, Japan, and Britain -- to discuss their response to Russia's unrecognized annexation of Crimea.
U.S. Secretary of State John Kerry and Russian Foreign Minister Sergei Lavrov are also expected to hold face-to-face talks on the Ukraine crisis on the sidelines of the nuclear summit in The Hague.
The United States and the EU have separately already imposed visa bans and asset freezes on some members of the inner circle of Russian President Vladimir Putin.
In Kyiv, meanwhile, acting Ukrainian President Oleksandr Turchnyov has given orders to the Defense Ministry to withdraw all Ukrainian military forces from Crimea.
He said the order was given due to what he said are threats by the Russian military to the lives and health of Ukrainian servicemen and their families in Crimea.
The announcement came just hours after Russian troops forced their way inside a Ukrainian marine base in Feodosia.
Russia has been taking control of scores of military institutions across Ukraine's Crimean Peninsula.
Russian Defense Minister Sergei Shoigu arrived in Crimea on March 24 to inspect the Russian Black Sea Fleet in Sevastopol and meet with secessionist Prime Minister Sergei Aksyonov.
Shoigu appointed Rear Admiral Denis Berezovsky as deputy commander of Russia's Black Sea Fleet.
Berezovsky had been appointed commander of Ukraine's navy earlier this month but announced he was instead supporting the pro-Russian government in Crimea.
Russian forces have seized dozens of Ukrainian naval ships in the past few days.
The hastily called G7 meeting in The Hague comes one day after NATO’s top military commander, General Philip Breedlove, said Russian troops massed on Ukraine's borders pose a threat to Moldova’s separatist Transdniester region.
"There is absolutely sufficient force postured on the eastern border of Ukraine to run to Transdniester, if the decision was made to do that," he said. "And that is very worrisome."
Breedlove accused Russia of acting more like an adversary than a partner, saying Moscow was using frozen conflicts and the possibility of confrontation with Russia as a "tool" to discourage EU and NATO membership.
Acting Ukrainian Foreign Minister Andriy Deshchytsya told U.S. television on March 23 that he believed the chances of war between his country and Russia are growing.
With reporting by Reuters, Interfax, dpa, and AFP