US and European leaders on Monday promised to respond to discoveries of mass graves and other apparent atrocities in the outskirts of kyiv with tougher sentences for Vladimir Putin.

Why is this important: Western sanctions and arms shipments came abruptly after the invasion, with two major constraints: Europe’s dependence on Russian energy and the reluctance of NATO countries to risk war beyond borders of Ukraine. Their calculations may now change, if only slightly.

Driving the news: National Security Adviser Jake Sullivan said Monday afternoon that the United States would impose new sanctions after the discovery of what he described as war crimes in Bucha. Ukrainian troops retaking the town near kyiv found civilians with their hands tied who had apparently been shot at close range.

• Sullivan claimed it was not abnormal but “part of the plan” of a Russian regime determined to impose “a reign of terror in the occupied territories in Ukraine”.
• Russia withdraws from its positions near the Ukrainian capital. Sullivan said Russia was moving its objective and troops east, hoping to “encircle and overwhelm the Ukrainian forces” there.
• Russian officials and state media have denied responsibility for the Bucha massacre and in some cases blamed Ukraine for carrying it out (claims denied by witnesses, journalists and satellite images).

Between the lines: The United States has already achieved many of the obvious sanctions targets, but measures such as removing all Russian banks from the SWIFT transaction system or applying secondary sanctions on oil exports are still possible.

French President Emmanuel Macron spoke out on Monday in favor of new sanctions on Russian oil and coal – but he did not mention Russian gas, which accounts for 40% of Europe’s supply, Axios’ Zach Basu reports.

• EU countries have paid Russia more than $20 billion for fossil fuels since the invasion began, and Russia is expected to earn $320.7 billion from energy exports this year, or up 36% from 2021, according to Bloomberg.
• Momentum for a sanctions package that would ban oil and coal imports is growing, but European officials – including in the German government – ​​took contrasting positions on Monday on whether the timing has come to take a hard line on gas.
• Lithuania is moving forward on its own, becoming the first EU country to completely stop importing Russian gas.

More American weapons, including drones and armored vehicles, are also on the way as part of a package announced on Friday. Sullivan said new shipments would be announced soon.

• NATO countries are showing increasing willingness to provide weapons that could enable Ukraine to go on the offensive, including tanks.
• But they have yet to supply the types of aircraft and air defense systems Ukrainian President Volodymyr Zelensky has publicly lobbied for. A plan to send S-300 missile defense systems from Slovakia to Ukraine appears to have hit a snag.

President Biden said on Monday that, in addition to providing Ukraine with weapons to continue its fight, it would also help document evidence for a future war crimes trial against Vladimir Putin.

• Former International Criminal Court prosecutor Alex Whiting told Axios’ Laurin-Whitney Gottbrath that there is clear evidence of war crimes in Bucha, but “the challenge will be to prove who was responsible, and how far ‘where is it going?’
• Whiting said it would be crucial to have investigators on the ground as soon as possible to speak to witnesses to try to determine which units were involved and who gave the orders.

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