U.S. President Barack Obama and European leaders, in a show of solidarity, agreed on Monday to impose a wider set of sanctions against Russia's financial, defense and energy sectors in the wake of the shootdown of a passenger jet over Eastern Ukraine, a top Obama aide said.
It is still unclear "exactly who pulled the trigger" to down the Malaysian jet, but he said Russia is culpable.
The coordinated measures come as the United States warned of a Russian troop buildup along the border with eastern Ukraine and the shipment of new sophisticated weapons to pro-Russian separatists.
EU diplomats reached a preliminary deal on Monday on a list of people, including associates of Russian President Vladimir Putin, and firms to be subject asset freezes as part of tougher measures over Russia's actions in Ukraine, EU diplomats said.
The new list of names is expected to be published on Tuesday or Wednesday and is in addition to 87 people and 20 organizations already subject to EU sanctions.
The three diplomats speaking on condition of anonymity said they could not give full details, but the persons targeted included people and companies, who are supporting or benefit from destabilization of Crimea and Russia's annexation of Crimea.
"The list includes individuals, cronies and entities,'' one diplomat said. Another said the list was "subject to some legal refinement'' and would be signed off on Tuesday when EU diplomats continue talks.