President Obama said the measures are aimed at 'changing Putin's calculus' on Ukraine, and that further 'Russian aggression' could trigger more sanctions.
The interim government said it had 'obtained US support' for operations against pro-Russian militias, which it restarted after saying that a local politician was found dead and tortured.
Less than 24 hours after it was signed by officials from Russia, Ukraine, the US, and the EU, the ambitious roadmap to defuse Ukrainian tensions was showing cracks.
Kiev says it has begun operations to displace pro-Russia protesters holding buildings in the country's east, though there have been few signs of activity so far.
Russia continues to deny NATO accusations that it is gathering troops on the border as it hastens to prepare for a possible cutoff of essential Ukrainian-made military parts.
NATO's top military commander says that he will present a package of measures next week laying out how the alliance will respond to the Russian buildup along Ukraine's borders.
Kiev gave protesters in the east 48 hours to come to the table. But in both Donetsk and Luhansk, armed demonstrators remained behind their barricades.
This week's roundup of Good Reads includes the impact of drinking wells in Uganda, why an American reporter resigned from RT, Albanian mountain women who live as men, the continuing plight of bluefin tuna, and acoustic wonders.