TOP WRAP 12-Russia bombards and U.S. imposes sanctions as Ukraine urges decisive help

(Adds Biden, Zelenskiy quotes, rouble extends gains, EU sanctions detail)

* Zelenskiy says rhetoric on sanctions not enough

* U.S. targets Russia banks, Putin's daughters, with sanctions

* Hungary breaks with EU over gas, others question coal ban

* Biden wants Russia expelled from G20, says Yellen

By Natalia Zinets and Conor Humphries

LVIV, Ukraine/DUBLIN, April 6 (Reuters) - Russian forces bombarded cities in Ukraine as the United States imposed more sanctions on Wednesday after civilian killings widely condemned as war crimes and Ukraine's President urged a decisive Western response amid divisions in Europe.

Russia's 42-day-long invasion has forced more than 4 million people to flee abroad, killed or injured thousands, left a quarter of the population homeless, turned entire cities into rubble and prompted a slew of Western restrictions on Russian elites and the economy.

The new measures announced by Washington included sanctions on President Vladimir Putin's two adult daughters, days after the grim discovery of civilians shot dead at close range in Bucha, north of Kyiv, when it was retaken from Russian forces.

"We're going to keep raising the economic costs and ratchet up the pain for Putin, and further increase Russia's economic isolation," U.S. President Joe Biden said.

The United States wants Russia expelled from the Group of 20 major economies forum, and will boycott a number of meetings at the G20 in Indonesia if Russian officials show up, according to Treasury Secretary Janet Yellen.

But Ukrainian President Volodymyr Zelenskiy was critical of some in the West and said he could not tolerate "any indecisiveness."

"The only thing that we are lacking is the principled approach of some leaders - political leaders, business leaders - who still think that war and war crimes are not something as horrific as financial losses," he told Irish lawmakers.

European Union diplomats failed to approve on Wednesday new sanctions, as technical issues needed to be addressed, including on whether a ban on coal would affect existing contracts, sources said.

EU member Hungary said it was prepared to meet a Russian request to pay roubles for its gas, breaking ranks with the rest of the bloc and highlighting the continent's reliance on imports that have held it back from a tougher response on the Kremlin.

Western policymakers have denounced the killings in Bucha as war crimes, and Ukrainian officials say a mass grave by a church there contained between 150 and 300 bodies.

Moscow denied targeting civilians there or elsewhere. Russia's foreign ministry said that images of bodies in Bucha were staged to justify more sanctions against Moscow and derail peace talks with Kyiv.