Russia has prepared more tanks to be sent to Ukraine, according to a senior US official.
"We have information that additional tanks departed from a deployment site in southwest Russia yesterday," said the official, who spoke on condition of anonymity.
The US has intensified talks with the EU on possible "scalpel" sanctions against Russia's defense and high-tech industries, the source added.
"The idea here is to deny Russia the kinds of investment and next-generation technology that it needs to continue to grow," the source said. "It (the talks with the EU) has intensified over the last week."
More top news
The Royal Marine shot a Taliban fighter in 2011 and had his initial murder conviction quashed earlier this month.
The report found one man had voted twice in the EU referendum and a Tory councillor who had been jailed for submitting a false address.
Weather set to improve with plenty of sunshine by Saturday