BRUSSELS (AP) -- The European Union suspended talks with Russia on a wide-ranging economic pact and on a visa deal Thursday, punishing Moscow for its military incursion into the Crimean Peninsula of Ukraine.
EU leaders made the announcement at an emergency summit and threatened further sanctions if Russia does not quickly engage in talks to end the crisis.
The move in Brussels came on the heels of sanctions by the Obama administration in Washington, D.C., which imposed visa restrictions on pro-Russian opponents of the new Ukrainian government in Kiev, also clearing the way for financial sanctions.
EU President Herman Van Rompuy said further measures could include travel bans, asset freezes and the cancellation of an EU-Russia summit if Moscow does not quickly end aggression and join talks to halt the crisis.
The sanctions on both side of the Atlantic aimed to rein in Europe's gravest geopolitical crisis in a generation.
Van Rompuy called the Ukraine crisis the "most serious challenge to security on our continent since the Balkan wars" of the 1990s.
The EU put on ice talks on a wide-ranging economic agreement and on granting Russian citizens visa-free travel within the 28-nation bloc, a goal that Moscow has been pursuing for years.
The decision followed tough negotiations between member states divided over how to react to the Russian aggression.
"Not everyone will be satisfied with the decision but I should say that we did much more together than one could have expected several hours ago," said Polish Prime Minister Donald Tusk.
He stressed that further sanctions will kick in in the coming days unless Russia stops its "aggressive steps" on the Crimean peninsula and engages in a meaningful dialogue to defuse the crisis.
Tusk said there was "no enthusiasm" in Europe on sanctioning Russia, but he called the moves inevitable given the country's blatant violation of international rights by its actions in Crimea.