* Russia analysts ask if Trump has changed approach

* 'We have hit an inflection point,' Western diplomat says

* Putin may have 'overplayed his hand,' U.S. official says

By Arshad Mohammed and John Walcott

WASHINGTON, March 15 (Reuters) - By imposing new sanctions on Russia and condemning a suspected Russian chemical attack in Britain, Washington has hinted at a tougher stance toward Moscow despite President Donald Trump's stated desire for better ties.

In the most significant steps the United States has taken against Russia since Trump took office amid U.S. intelligence agency allegations that Moscow tried to help him win the 2016 election, the U.S. Treasury slapped sanctions on 19 Russian citizens and five entities for election meddling and cyber attacks.

While the Treasury put off targeting oligarchs and officials close to Russian President Vladimir Putin, it said further sanctions were coming and for the first time blamed Moscow for cyber attacks stretching back at least two years that targeted the U.S. power grid, including nuclear facilities.

After initially equivocating about a chemical attack on a former Russian double agent in Salisbury, England, the White House joined a statement by the leaders of Britain, France and Germany in which they said they "abhor the attack" and blamed Moscow for it.

Moscow has denied any involvement in the poisoning.

Thursday's actions have caused some Russia analysts to ask whether the administration is taking a more confrontational stance despite Trump's repeated statements in the election campaign that he wanted a better relationship with Moscow, his praise for Putin and apparent reluctance to criticize the Russian leader.

"I think we have hit an inflection point in the current administration’s approach towards Russia," said a diplomat who spoke on condition of anonymity. "There has been a shift in balance."

The diplomat attributed the evolution partly to a clash between U.S.-backed and Russian-backed forces in the Syrian city of Deir al-Zor in February; Russia pounding Syria's eastern Ghouta enclave of anti-government rebels with air strikes during the past month; And Putin showing a video on March 1 of a weapon appearing to hover over what looked like a map of Florida, home to Trump's Mar-a-Lago resort.

"Those three things, taken together, have caused a shift in analysis in parts ... of the administration," said the diplomat.

Other Russia analysts said it was not clear whether Trump had fundamentally changed his stance.

Eugene Rumer, a former U.S. national intelligence officer for Russia, suggested Trump's approach may ultimately be guided by Special Counsel Robert Mueller's investigation into whether Russia meddled in the election campaign. The Kremlin denies interfering. Mueller is also investigating any potential collusion between the Trump campaign and Moscow officials, something Trump denies.