Ukraine needs "a ceasefire not in name, but ceasefire in substance," Pavlo Klimkin told reporters in the Swiss city on the sidelines of a meeting of the Organization for Security and Cooperation in Europe (OSCE) focused on the crisis in his country.
"It's about delivery for me. It's not about promises, it's about real delivery on the ground. It's what we do and not what we say," he said.
Shortly after Klimkin spoke, Ukraine's military said in Kiev that six soldiers were killed in the past 24 hours.
On Thursday Kiev and pro-Russian rebels said they had agreed to halt fire next Tuesday, in an unexpected announcement that provided a glimmer of hope that fighting across the eastern rustbelt of the ex-Soviet nation was nearing an end after eight months that saw 4,300 people killed and shattered Moscow's ties with the West.
Russian Foreign Minister Sergei Lavrov said Friday he hoped the latest ceasefire would lead to a final agreement to stop the fighting.
"It is a very difficult situation but I hope parties have come close to concluding a final agreement," he told reporters on the sidelines of the OSCE meeting.
Russia has repeatedly denied accusations from the West that it is arming and militarily supporting the rebels in eastern Ukraine.
But Klimkin insisted that "Russian-backed terrorists" were currently shelling Ukrainian troops up to 40 times a day, resulting in numerous deaths among troops and civilians.
He stressed that the "overriding challenge, the overriding problem for our security was always a lack of trust (and) now we have no trust whatsoever."
What is needed is therefore "deeds on the ground... to achieve a real ceasefire," Klimkin said, calling for "real control for the Russian-Ukrainian border".
He also said "a breakthrough on hostages" was needed, insisting "terrorists" are still holding more than 500 Ukrainians captive.
And he demanded the cancellation of the "so-called elections of November 2", held by pro-Russian separatist rebels in eastern Ukraine and not recognized by Ukraine or the West.
"We need everyone to deliver on the ceasefire," he said.
Meeting such conditions, he said, would provide "a clear line for the future and it will bring additional momentum for de-escalation in Donetsk and Lugansk, and we are very hopeful for that".
Ukraine is working to organize a meeting next week of the so-called Trilateral Contact Group on Ukraine, made up of OSCE negotiators and envoys representing Ukrainian President Petro Poroshenko and Russian leader Vladimir Putin, along with "the terrorists from Donetsk and Lugansk," Klimkin said.
"Then we will see."
Virtually all of the more than 50 foreign ministers attending the two-day OSCE conference in the northern Swiss town of Basel had voiced support for Ukraine, he said, "except Russia".