(CNN) — Western powers increased pressure on Russia on Wednesday to talk to the new government in Kiev in a bid to ease tensions over Russia's military intervention in Ukraine's Crimea region.
Russia has been warned that possible sanctions will be on the agenda when European Union leaders meet Thursday in Brussels, Belgium, if no progress is made in ending the high-stakes showdown.
But such measures may not only hurt Russia. In a tit-for-tat move, Russian lawmakers are drafting a law that would allow Russia to confiscate assets belonging to U.S. and European companies if sanctions are slapped on Moscow, Russian state media reported.
The diplomatic maneuvers come as world leaders meet in Paris for talks that were intended to focus on Lebanon. Instead, Ukraine will likely dominate the agenda.
Russian forces remain in effective control of Crimea, a Black Sea peninsula where Russia has a large naval base, in a tense standoff with Ukrainian forces loyal to the new interim government in Kiev.
U.S. Secretary of State John Kerry and his Russian counterpart, Sergey Lavrov, are due to meet in Paris.
But UK Foreign Secretary William Hague said what happens at the EU meeting on sanctions "will be partly determined by Russia's willingness to sit down with Ukraine."
If no progress can be made on de-escalating the situation, then there will be "costs and consequences," Hague said.
"It will be a test this afternoon of whether Russia is prepared to sit down with Ukraine. And we will strongly recommend that they do so."
Kerry: Clear legal obligations at stake
Hague's comments came after he, Kerry and Ukrainian Foreign Minister Andrii Deshchytsia discussed their next steps ahead of Lavrov's arrival in the French capital.
Kerry reminded Moscow that it had, like Washington and London, signed an agreement in 1994 when Ukraine agreed to give up nuclear weapons "to refrain from the threat or use of force against the territorial integrity or political independence of Ukraine."
There are "very clear legal obligations that are at risk in this," Kerry said.
Deshchytsia said he hoped for bilateral and multilateral consultations with Russia.
At issue is Russia's insistence that the new government in Ukraine is not legitimate, which means it does not recognize its authority.
Western powers argue in return that ousted President Viktor Yanukovych fled the country, leaving a void that had to be filled. The interim government was voted in with a large majority in parliament, including by members of Yanukovych's Party of Regions, they point out.
France: Invasion violates international law
The threats of sanctions and countermoves are the latest forays in a war of words over Russia's military intervention in Ukraine's southern Crimea region.
On Tuesday, a defiant Russian President Vladimir Putin denied Russian troops were in Crimea but reserved the right to take military action to protect the safety of ethnic Russians in eastern Ukraine.
He also slammed the interim government, which replaced Yanukovych, a Russian ally, as illegitimate.
French Foreign Minister Laurent Fabius set out a very different point of view Wednesday as he declared that sanctions could be in the cards.
"The invasion of one country into another is contrary to all international laws. We must return to dialogue and to bear in mind that Ukraine should work with Russia and the EU," Fabius said via Twitter.
"We cannot accept, we members of the international community, a country that invades another."
On Tuesday, Kerry accused Russia of making up reasons for intervention in Ukraine, saying "not a single piece of credible evidence supports any one of these claims."
NATO members are set to meet with Russia's ambassador to the alliance Wednesday amid concerns the crisis could spread beyond Ukraine.
And NATO Secretary General Anders Fogh Rasmussen and Ukrainian Prime Minister Arseniy Yatsenyuk are due to meet Thursday.
EU Commission President Jose Manuel Barroso announced Wednesday in Brussels that the EU would offer an aid package worth 11 billion euros to Ukraine. He said the package was "designed to assist a committed, inclusive and reforms oriented" Ukrainian government.
Barroso confirmed on Twitter the aid package would consist "of immediate short and medium term measures offering trade, economic, technical and financial assistance to #Ukraine."
During his visit to Kiev on Tuesday, Kerry announced the United States will give Ukraine's new government $1 billion in loan guarantees. Senior U.S. administration officials told CNN the move would help insulate the Ukrainian economy from the effects of reduced energy subsidies from Russia.
Meanwhile, the EU acted to freeze what it suspects are misappropriated Ukrainian state funds held in Europe by 18 people. It did not say who the 18 are.
German Chancellor Angela Merkel is trying to construct what a senior U.S. administration official characterized as an "off-ramp," or way out, for Putin by having international observers in Crimea to ensure ethnic Russians' rights aren't violated.
President Barack Obama floated this idea in a call Saturday with Putin, and Obama and Merkel talked about it Tuesday.
Lavrov: Military coup in Ukraine
Lavrov, speaking in Madrid, Spain on Wednesday, showed no signs of budging from the position taken by Putin a day earlier.
The Russian foreign minister said the crisis had begun when the international community failed to react to the anti-government protests that preceded Yanukovych's ouster.
"There was a military coup, and the legitimate president was removed by methods which were not in the constitution or legislation," Lavrov said.
"If we are so lenient to the people who are trying to govern our neighbor, everyone must realize a bad example can be spread and there shouldn't be any double standards."
Lavrov repeated Putin's denial that Russian troops are in control in Crimea, saying the troops in question are "self-defense" forces over whom Russia has no control.
Decisions on whether international observers should be sent into Ukraine are for leaders in the country to make, he said. He pointed out that the newly installed pro-Russian government in Crimea does not see the authorities in Kiev as legitimate.
"This problem is multifaceted. In order to calm the situation down everyone must act in accordance with the law," he said.
Moscow wants to see an agreement signed February 21 between the government of the ousted Yanukovych and the opposition to be the basis of any settlement. It promised new elections, constitutional reforms and the disbanding of illegal armed groups
Fears of instability
The Organization for Security and Co-Operation in Europe, a regional security bloc, said Wednesday it was sending 35 unarmed military personnel to Ukraine in response to a request from Kiev.
No violence has erupted in Crimea, where Russian troops currently control military bases and key installations, but the situation remains volatile.
Andriy Parubiy, secretary of Ukraine's Security and Defense Council, told reporters in Kiev Wednesday that the situation in Crimea was more calm a day earlier.
Parubiy said Russian forces had not made any new military gains on the peninsula but warned of the danger of new attempts by pro-Russian protesters to take over government buildings in eastern and southern Ukraine.
Warning shots were fired Tuesday by the Russia side during a confrontation with Ukrainian forces at a military base near the port of Sevastopol before the situation was defused.
Col. Sergei Astakhov, assistant to the chief of the Ukrainian Border Service, told CNN its officers have increased the level of security checks at the Ukrainian-Russian border, particularly in the southeast.
Over the past day, he said, they have turned back more than 300 people attempting to enter from Russia, whom they suspected of possible participation in mass disturbances and extremist activities.
On Tuesday, Putin said he had ordered Russian troops who were on mass military exercises close to the border with Ukraine back to their bases -- which many observers saw as a positive sign.