The leaders of France and Germany have said that they will deliver a new peace initiative to the Ukrainian and Russian capitals.
French President Francois Hollande said he and German Chancellor Angela Merkel would travel to Kiev on Thursday and then to Moscow the following day, with a proposal "based on the territorial integrity of Ukraine".
In a sign of the importance of the initiative and urgency of the situation, this will be Merkel's first trip to Moscow since Ukraine's conflict broke out a year ago.
"It will not be said that France and Germany together have not tried everything, undertaken everything to preserve the peace," Hollande said.
Merkel's spokesman called for a peaceful settlement of the conflict.
John Kerry, US secretary of state, also arrived in Ukraine on Thursday to show support for the government, and call for a diplomatic solution to the conflict.
In a joint press conference with Ukrainian President Petro Poroshenko, Kerry urged Russia to honour a peace deal signed in Belarus, by pulling back weapons and Russian fighters from border.
"We want a peaceful resolution," Kerry said. "Russia has to make a choice."
Kerry also unveiled $16m in fresh US humanitarian aid, particularly to help those displaced in the war-torn east, Reuters news agency reported.
The high-level visits came a day after rocket salvos hit a previously safe section of rebel stronghold of Donetsk, killing at least five people and damaging a hospital, schools and kindergartens, rebels said.
The European and US politicians will try to explore ways to end the conflict that has claimed more than 5,100 lives in the past nine months.
On Wednesday, Poroshenko said that he was confident that the US would agree to give weapons to Ukraine's army in its fight against the rebels.
But during the joint press conference on Thursday, neither Kerry nor Poroshenko mentioned a weapons assistance deal.
President Barack Obama is opposed to providing lethal assistance, but the surge in fighting has reportedly spurred the White House to review the policy.
Germany and France strongly oppose supplying weapons to Ukraine, however. Merkel's spokesman indicated the issue would be discussed when Merkel meets Obama in Washington next week.
"We will not deliver any lethal weapons," Merkel spokesman Steffen Seibert said on Wednesday. "We are convinced that there can be no military solution to this already very bloody conflict."
A spokesman for Ban Ki-moon said in a statement that the UN secretary-general condemned indiscriminate shelling and called on both sides in the conflict to immediately move their military positions away from densely populated civilian areas.
Source: Al Jazeera And Agencies