Ukraine's President Petro Poroshenko (L) speaks during news conference next to German Chancellor Angela Merkel after a meeting at the Chancellery in Berlin, Germany, May 13, 2015. (Reuters Photo)
Ukrainian President Petro Poroshenko called the Minsk agreement a "pseudo-ceasefire" in an interview due to be aired on German television channel ZDF later on Wednesday.
Despite Kiev and Moscow agreeing to a truce in February, shooting has continued around the coastal town of Shyrokyne, near the strategic port city of Mariupol.
Poroshenko and German Chancellor Angela Merkel held talks in Berlin on Wednesday. Ahead of their meeting, Merkel said the Minsk agreement was still being violated on a regular basis.
On Wednesday, US Secretary of State John Kerry called for a halt to fighting around the Ukrainian coastal town of Shyrokyne as NATO backed his demand that Russia fully implement a Ukraine ceasefire agreement.
Excerpts of the interview released in advance showed that when asked about whether the port city of Mariupol was under threat from Russian separatists who wanted to create a land corridor to Crimea, Poroshenko said: "Clearly".
Russia denies it is providing troops or arms to pro-Russian rebels who launched a separatist uprising in April of last year. It accuses Kiev of breaching the February ceasefire agreement.
Capture of Mariupol port could help separatists cement a hold on eastern Ukraine's Lugansk and Donetsk regions. Kiev fears it could also provide the pivot for an advance along Ukraine's south coast to link up with Crimea, annexed by Russia last March.
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