Petro Poroshenko said he and Romanian President Klaus Iohannis agreed that "discussions related to cancelling sanctions imposed on Russia cannot take place until the aggression stops."
Security was the main focus of talks during Poroshenko's one-day visit Thursday to neighboring Romania. Fighting in eastern Ukraine between Russia-backed separatists and government troops has left 9,100 dead since 2014.
Poroshenko says "an end to sanctions will be an unmitigated danger for resolving the situation in Donbass. Russia will continue its aggressive actions," according to AP.
The two leaders agreed on the idea of a NATO Black Sea fleet "to consolidate the presence" of the alliance. Romania is a NATO member and is pushing for a fleet.