The United States along with their counterparts in Europe have readied a new round of penalties against Russia targeting its energy and financial sectors as part of a sanctions-in-waiting strategy that officials hope will enable the West to respond immediately if Moscow-backed insurgents seize more territory in Ukraine.
The penalties could start with banning more Russian government officials and businessmen from traveling and doing business in the West, US and European officials said. But they can climb dramatically to include new measures to crimp the country's all-important fuel exports, cut Russian banks off from international financial transactions and severely limit the capacity of Russian businesses to engage in lucrative business deals overseas.
The Americans and the Europeans are working off the same menu of contingency measures, though there is no agreement yet on what level of response would be appropriate for each type of infraction.
Secretary of State John Kerry told reporters this week that imposing additional sanctions on Russia "depends on what happens on the ground" and on President Vladimir Putin's support for fully implementing a February cease-fire in Ukraine.
If violence stops and separatists can reach a political agreement with Ukraine's Western-backed government in Kiev, sanctions can be rolled back, he said. But, "if President Putin chooses to play a double game and continues to allow the separatists to press forward, then obviously we have a very big challenge ahead of us."
The European Union will extend its current penalties on Russia next week, though officials said there is no consensus among its 28 members on new measures.
The new strategy for possible additional sanctions reflects the lessons learned by US and European officials over the last 16 months during which Russia occupied and annexed Ukraine's Crimean Peninsula and, Western nations say, fueled an insurgency within eastern Ukraine.
The combined US-European response has hit Russia's economy hard. Combined with a drop in fuel prices, sanctions spurred a crash in the ruble and have forced the Kremlin to dig ever deeper into its cash reserves to keep the economy afloat.
But for all that pain, it has done little to sway Putin. The US says his military continues to direct separatist and Russian forces in battlefield attacks. It has stepped up the level of equipment provided to insurgents and is now using drones and other advanced techniques in joint training.
On Thursday, State Department spokesman John Kirby expressed concerns about several attacks on Ukrainian positions beyond the truce line, saying "combined Russian-separatist forces" used heavy weapons banned by the cease-fire. "Russia bears direct responsibility for these aggressive actions," he told reporters, and warned of "increased costs" for Moscow if territory is seized.
Slowness was among the main flaws that hampered early US and European efforts to counteract Putin, according to officials, who weren't authorised to talk about private sanctions deliberations publicly and demanded anonymity. After rebel offensives, sanctions often took weeks to coordinate.
By the time they arrived, insurgent forces would be entrenched and Putin was prepared to accept the economic bullet, they said.
The new approach is geared around speed, officials said, with sanctions "locked and loaded" ahead of what could be a volatile summer.
Officials fear a renewed Russian-led offensive in eastern Ukraine, including the strategic port city of Mariupol, government-held parts of the Donetsk and Luhansk provinces, and the city of Kharkiv, Ukraine's second-largest.
The Obama administration has insisted on coordinating its response with Europe to maximize the economic impact of any future sanctions. However, European Union political machinations often have stalled the process as member states object to measures that would hurt their economies. The new strategy seeks to streamline the process by getting states to agree ahead of time on acceptable targets.
The guiding principles of any future sanctions, officials said, are that they hurt Russia more than the US or any individual European economy, be relatively easy to establish, and prove sustainable and enforceable.
However, officials on both sides of the Atlantic said they hoped to avoid the scenario of any new sanctions, expressing cautious optimism in a series of "working group" discussions involving Ukraine, Russia and separatist leaders. The West hopes the eastern areas will be content with greater autonomy within Ukraine and that violence will end.