Can 4 world leaders end fighting in Ukraine?

The leaders of Germany, France, Russia and Ukraine aim to hold a summit in Minsk this week as they try to stem fighting in eastern Ukraine, officials said Sunday.

The plan for a meeting Wednesday in the Belarusian capital emerged from a phone call between German Chancellor Angela Merkel, French President Francois Hollande, Russian President Vladimir Putin and Ukrainian President Petro Poroshenko. Merkel's spokesman, Steffen Seibert, described the call as "intensive."

The aim is to draw up a package of measures that breathes new life into a much-violated September peace plan. Seibert and the French government said preparations for the summit will take place Monday in Berlin, without elaborating.

"They (the leaders) expect that their efforts during the Minsk meeting will lead to the swift and unconditional cessation of fire by both sides," Poroshenko's office said in a statement.

Putin also confirmed that a summit was being planned for Wednesday in Minsk, but said it might not come about.

"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, Russian news agencies reported.

A separate meeting between the signatories to last September's accord, including Russia, Ukraine and representatives of separatists in eastern Ukraine, will also take place in Minsk by Wednesday, Seibert said.

Before the summit Merkel, who met Friday night in Moscow with Putin, is scheduled to meet with President Barack Obama in Washington Monday on a previously scheduled trip.

At an international security conference in Munich, U.S. Secretary of State John Kerry said the U.S. and its European allies are "united in our diplomacy" on Ukraine. He said the U.S. supports efforts by France and Germany to produce a new plan to end the conflict that is now raging in east Ukraine.

Kerry denied that there is a U.S.-Europe rift over how to respond to the crisis and how to deal with Russia's role in it despite a debate over whether to arm the government in Kiev.

"There is no division, there is no split," Kerry said. "I keep hearing people trying to create one. We are united, we are working closely together."

His comments came amid reports of a deep trans-Atlantic rift over the Obama administration's consideration of providing defensive weaponry to Kiev. Germany and France oppose such a move, saying it could lead to an escalation and that they do not believe the conflict can be resolved militarily. Russia, which is accused of supporting separatist rebels in eastern Ukraine, has said the introduction of U.S.-supplied weaponry will have grave consequences.

German Foreign Minister Frank-Walter Steinmeier, speaking alongside Kerry, reiterated that he considers delivering weapons "not just highly risky but counterproductive."

Kerry said the United States agrees that there is no military solution to the Ukraine crisis that has now killed more than 5,300 people, according to the United Nations.

At the same time, U.S. officials say Obama is rethinking his previous opposition to sending arms to Ukraine despite fears it could lead to a proxy war between Washington and Moscow. The officials have, however, suggested that any such weaponry would be intended to help Kiev defend itself once a peace agreement is reached.

Kerry likened the U.S.-European debate over arms to previous consultations over the breadth and strength of sanctions against Russia.

"The discussion taking place today is absolutely no different — it's tactical, it is not strategic," Kerry said. "On the fundamental goal with respect to Ukraine, we are absolutely united ... we want a diplomatic solution."

Reacting to the announcement of the proposed Minsk summit, State Department spokeswoman Jen Psaki said Kerry will "remain closely engaged" as talks continue.

Republican Sen. John McCain, the chairman of the 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?"