Ukrainian government forces are pressing ahead with a military offensive against pro-Russian separatists in the country's east as Ukraine, Russia, Germany, and France prepare for a crisis meeting of foreign ministers in Berlin.
A French diplomatic source said that the meeting in Berlin had no "precise objective" but will present "an opportunity to work on peace efforts."
Russia's Foreign Ministry said in a statement that Foreign Minister Sergei Lavrov backed the idea of the July 2 meeting with France's Laurent Fabius and Ukraine's Pavlo Klimkin during a telephone conversation with his German counterpart, Frank-Walter Steinmeier.
NATO Secretary-General Anders Fogh Rasmussen is also due to discuss the Ukraine crisis when he meets in Berlin on July 2 with Steinmeier and German Chancellor Angela Merkel.
Meanwhile, National Security and Defense Council spokesman Andriy Lysenko said on July 2 that four Ukrainian troops were killed as forces carried out more than 100 attacks on rebel positions and cleared separatists from three villages in the last day.
Ukrainian parliament speaker Oleksandr Turchynov told lawmakers that "the armed forces and the National Guard are continuing the offensive on terrorists and criminals. The actions of our military are effective and are having results."
A military spokesman said rebels fired a shoulder-launched missile that struck and damaged a SU-24 attack plane.
Ukrainian President Petro Poroshenko ended a 10-day unilateral cease-fire late on June 30, saying it had accomplished little to solve the crisis and had been used by the militias to regroup and stock up on heavy weaponry from Russia.
The Ukrainian Foreign Ministry said 27 servicemen were killed during the course of the cease-fire.
U.S. State Department spokeswoman Marie Harf said late on July 1 that Poroshenko "has a right to defend his country," adding that "it takes two to keep a cease-fire."
Lavrov, however, said Poroshenko's decision had started “a new cycle of bloodshed" with "unpredictable consequences."
Separately, Russian President Vladimir Putin reacted to Poroshenko's deicison by saying the Ukrainian leader "took upon himself the responsibility for unleashing battle actions in Ukraine."
Putin, speaking at a biannual meeting of Russian ambassadors in Moscow on July 1, accused the West of seeking to use the crisis in Ukraine to destabilize the region.
Putin said that "Russia will continue to protect ethnic Russians abroad, including using political, economic, and humanitarian means."
In Brussels, the European Union on July 1 decided not to immediately impose new sanctions on Russia, saying the picture on the ground remained "mixed."
However, EU diplomats were quoted as saying the governments decided that "the preparation of sanctions will be intensified."
Sources said the ambassadors will convene again on July 7 to discuss the situation, and that EU experts were working on sanctions targeting specific people or companies.
Meanwhile, Ukrainian military spokesman Oleksiy Dmytrashkovskyy said government forces launched artillery bombardments and air strikes against separatist positions.
Dmytrashkovskyy said rebels had fired on an SU-25 attack aircraft, damaging it, but that the plane had managed to land safely at its base. He denied a rebel report that a military helicopter had been brought down.
Kyiv said its forces regained control of the Dovzganskyy border crossing in Lugansk, on the country's border with Russia, while rebels claimed they took control of the Luhansk airport.
In the city of Donetsk, reports said the separatists took over the Interior Ministry compound after hours of gunbattles.
Separatists in the Donetsk region said four people were killed when a shuttle bus was hit by gunfire in the city of Kramatorsk, without giving further details.
A separatist leader in Donetsk, Miroslav Rudenko, told Russia's Interfax news agency that fighting had broken out in Kramatorsk, the village of Karlivka, and at Donetsk's airport.
Witnesses also told local media that a tank battle was ongoing in the area of Karlivka, a village northwest of Donetsk.
With reporting by AFP, Reuters, and Interfax