By Jeff Mason and Steve Holland
WASHINGTON (Reuters) - The world is reassessing its relationship with Russia after its invasion of Ukraine, the White House said on Friday, shortly before President Barack Obama embarks on a European trip to bolster allies' resolve to impose tough sanctions on Moscow.
Obama will arrive in the Netherlands on Monday for a long-planned nuclear summit at The Hague, but his meetings with Group of Seven partners about Russia's annexation of Crimea will dominate the agenda.
In yet another blow to Western efforts for a diplomatic solution, Russian President Vladimir Putin signed laws completing the annexation of Crimea on Friday. The United States and its allies deemed the move illegal.
Susan Rice, Obama's national security adviser, told reporters that next week's trip would highlight the strength of U.S. alliances with European, Asian and Middle Eastern partners.
The international community, she said, was broadly rethinking its relationship with Russia after working to integrate it into the global economy and the "fabric of the international system" since the end of the Cold War.
"But that was predicated on an expectation that Russia would play by the rules of the road," Rice told a briefing.
"What we have seen in Ukraine is obviously a very egregious departure from that, and it is causing the countries and people of Europe and the international community - and, of course, the United States - to reassess, what does this mean and what are the implications?"
The immediate implications involve enacting tough sanctions on Moscow. Obama announced a new set of sanctions on Thursday and threatened to target major sections of the Russian economy, triggering a drop in shares on the Russian stock market.
Obama will press European partners, who have also imposed sanctions, to step them up to increase pain for Putin, one analyst said.
"These sanctions will be very difficult and very painful," said Heather Conley of the Washington-based Center for Washington-based Center for Strategic and International Studies.
"This is why the United States has to work very hard to convince the most reluctant, which will be our three strongest allies in Europe - Germany, France and the UK - that they have to put their economic interests aside," she said.
Rice said coordination between Washington and its European allies had been strong, and she hinted that the G7 meeting would include a discussion of whether to continue the G8, of which Russia is a part.
"Obviously, the G7 meeting will be an opportunity to deepen and continue that coordination, even as we have the chance to talk about how we step up our collective support for the people and the government of Ukraine and consider the optimum disposition of the G8/G7 mechanism going forward," she said.
Rice said the United States was skeptical of Russian assurances that troop movements on the Ukraine border were no more than military exercises.
(Additional reporting by Mark Felsenthal; Editing by Tom Brown)