MOSCOW, June 29, /ITAR-TASS/. Presidents Vladimir Putin of Russia, Pyotr Poroshenko of Ukraine and Francois Hollande of France, and German Chancellor Angela Merkel had a telephone conversation on Sunday to continue discussion of various aspects of the crisis in Ukraine, the Kremlin press service said, adding that it was a long conversation.

The leaders of Russia, Germany and France hailed the release of observers of the OSCE mission and the next round of consultations between the conflicting sides that had been held in Donetsk on June 27.

“The leaders stressed the necessity to make such contacts regular. They called on Poroshenko to extend the ceasefire regime for a longer period,” the press service said.

The leaders also looked at possible “commissioning OSCE inspectors to check points at the Russian-Ukrainian border,” the press service noted. Apart from that, Putin underscored the necessity of urgent humanitarian assistance to people living in Ukraine’s southeastern regions.

Francois Hollande and Angela Merkel noted certain progress from the point of view of the stabilization in the area of security. They also reminded that the European Union expected to see concrete results by June 30, in line with the resolution of the summit meeting that was held in Brussels last Friday. The leaders of France and Germany called on the Ukrainian and Russian presidents to pool their efforts to employ the mechanism of monitoring the observance of the truce regime and the situation at the border under the OSCE auspices.

“The leaders agreed to continue telephone contacts in the four-party format,” the press service said.

Putin, Hollande, Merkel and Poroshenko also touched upon issues related to the signing of the association agreement between Ukraine and the European Union in Brussels on June 27.