PARIS (AP) — U.S. Secretary of State John Kerry and Russian Foreign Minister Sergey Lavrov are advancing far different proposals on how to calm tensions and de-escalate the crisis in Ukraine as Russia continues to mass troops along its border with the former Soviet republic.

As Kerry called for Moscow to begin an immediate pullback of the troops, he also ruled out discussion of Russia's demand for Ukraine to become a loose federation unless Ukrainians are at the table.

While the United States and Russia agreed the crisis in Ukraine requires a diplomatic resolution, four hours of talks Sunday between Kerry and Lavrov failed to break a tense East-West deadlock over how to proceed.

"The Russian troop buildup is creating a climate of fear and intimidation in Ukraine," Kerry told reporters at the home of the U.S. ambassador to France after the meeting, which was held at the Russian ambassador's residence and included a working dinner. "It certainly does not create the climate that we need for dialogue."

The U.S. views the massing of tens of thousands of Russian soldiers, ostensibly for military exercises, along the border as an attempt to intimidate Ukraine's new leaders after Russia's annexation of the strategic Crimean peninsula, as well as a bargaining chip with the United States and the European Union, which have condemned Crimea's absorption into Russia and imposed sanctions on senior Russian officials.

Even if the troops remain on Russian soil and do not enter Ukraine, they create a negative atmosphere, Kerry said.

"The question is not one of right or legality," he said. "The question is one of strategic appropriateness and whether it's smart at this moment of time to have troops massed on the border."

Kerry proposed a number of ideas on troop withdrawals from the border and Lavrov, while making no promises, told him he would present the proposals to the Kremlin, according to U.S. officials.

Lavrov did not address the troop issue at a separate news conference at the Russian ambassador's house, instead arguing for Moscow's idea of Ukraine as a federalized nation with its various regions enjoying major autonomy from the government in Kiev. Russia says it is particularly concerned about the treatment of ethnic Russians and Russian speakers who live in southern and eastern Ukraine.

Ukraine can't function as a "unified state" and should be a loose federation of regions that are each allowed to choose their own economic, financial, social, linguistic and religious models, Lavrov said.

He said every time Ukraine has elected a new president, the country has adopted a new constitution, proving that "the model of a unified state doesn't work."

Ukrainian officials are wary of decentralizing power, fearing that pro-Russia regions would hamper its Western aspirations and potentially split the country apart. However, they are exploring political reforms that could grant more authority to local governments.

The United States has encouraged ongoing political and constitutional reform efforts that the government in Kiev is now working on, but U.S. officials insist that any changes to Ukraine's governing structure must be acceptable to the Ukrainians.

Kerry said the federation idea had not been discussed in any serious way during his meeting with Lavrov "because it would have been inappropriate to do so without Ukrainian input."

"It is not up to us to make any decision or agreement regarding federalization," he said. "It is up to Ukrainians."

"We will not accept a path forward where the legitimate government of Ukraine is not at the table," Kerry said, adding that the bottom line is, "No decisions about Ukraine without Ukraine."

Lavrov denied that Moscow wants to "split Ukraine."

"Federation does not mean, as some in Kiev fear, an attempt to split Ukraine," he said. "To the contrary, federation ... answers the interests of all regions of Ukraine."

Lavrov said he and Kerry did agree to work with the Ukrainian government to improve rights for Russian-speaking Ukrainians and disarm "irregular forces and provocateurs."

Sunday's meeting was hastily arranged two days after U.S. President Barack Obama and Russian President Vladimir Putin spoke by phone in a conversation in which Obama urged Putin to withdraw his troops from the border with Ukraine. Putin, who initiated the call, asserted that Ukraine's government is allowing extremists to intimidate ethnic Russians and Russian-speaking civilians with impunity — something Ukraine insists is not happening.

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