Summit to discuss Ukraine crisis
As Russian-backed separatists gain ground in eastern Ukraine, efforts to broker peace have appeared to gain momentum, with leaders of Germany, France, Russia and Ukraine announcing plans for four-way talks this week.
The proposed meeting on Wednesday in the Belarusian capital of Minsk emerged from a phone call between German chancellor Angela Merkel, French president Francois Hollande, Russian president Vladimir Putin and Ukrainian president Petro Poroshenko.
The aim is to revive the much-violated peace plan both sides agreed to in Minsk last September, and end a war that has now killed more than 5,300 people according to United Nations estimates.
Although the United States will not be at the negotiating table, a growing clamour in Washington to arm Ukraine will be on the minds of those present in Minsk.
US officials have said President Barack Obama is rethinking his previous opposition to sending weapons to Ukraine, despite fears of triggering a proxy war between Washington and Moscow.
While senior diplomats from the four countries meet in Berlin to prepare for the summit, Ms Merkel is expected to brief US officials in Washington during a previously scheduled trip.
"It's a fortuitous coincidence that Merkel is going to Washington and whatever she does, Obama will be informed," said Volker Perthes, director of the German Institute for International and Security Affairs.
The threat of US arms shipments won't harm the talks, he added, although "if the diplomatic efforts fail then the option to ship arms becomes more likely".
US Secretary of State John Kerry was keen to dispel the notion of a trans-Atlantic rift today, saying US and its European allies are "united in our diplomacy" on Ukraine.
Speaking at an international security conference in Munich, he said the US supports the efforts by France and Germany.
"There is no division, there is no split," Mr Kerry said. "I keep hearing people trying to create one. We are united, we are working closely together."
German foreign minister Frank-Walter Steinmeier, speaking alongside Mr Kerry, said he considers delivering weapons "not just highly risky but counterproductive".
But Republican senator John McCain, the chairman of the US Senate Armed Services Committee, insisted in Munich that "we must provide defensive arms to Ukraine".
"If we help Ukrainians increase the military cost to the Russian forces that have invaded their country, how long can Putin sustain a war that he tells his people is not happening?"
Aside from the military cost, Russia has also been struggling with the economic impact of western sanctions and low global oil prices.
While Ukraine's Mr Poroshenko raised the possibility that Wednesday's summit could provide a breakthrough after months of futile diplomacy, Mr Putin insisted that the four-way meeting would only happen if they agree on key points beforehand.
"We will be aiming for Wednesday, if by that time we are able to agree on a number of the positions that we recently have been discussing intensely," he told journalists in Sochi during a meeting with the president of Belarus.
Details of the proposals have not been revealed, but the main sticking points have emerged in the leaders' recent comments.
One is enforcing a peace deal. In Munich, Mr Poroshenko expressed opposition to any peacekeeper force, apparently reflecting concern that sending Russian peacekeeping troops into eastern Ukraine could result in a de-facto occupation.
But key to a real settlement is some mechanism for monitoring the Ukraine-Russia border to ensure that Russia is not sending troops or equipment to the separatists.
Ukrainian officials would have the Organisation for Security and Co-operation in Europe (OSCE) conduct such monitoring.
The status of the eastern regions remains contentious. Ukraine passed a law last year proposing what it called significant autonomy for the east, but rebels dismissed it as vague and meaningless.
Russia has pushed for "federalisation" of Ukraine, which would presumably give the east significant independence, but Ukrainian authorities oppose any federalisation.
How to separate the belligerents also remains unclear.
The Minsk agreement in September foresaw each side pulling back its heavy weapons nine miles (15km) from the lines of engagement.
But the rebels have taken control of more territory since then, implying that a new buffer zone would have to be mapped.
Kiev is refusing to allow the separatists a place at the top-level talks. Instead, their representatives would join a parallel meeting, to be held by Wednesday in Minsk, between the signatories to last September's accord.