BUCHAREST, Romania (AP) — Ukraine's president said Thursday that sanctions against Russia must stay in place as long as hostilities in eastern Ukraine continue.

President 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 said "an end to sanctions will be an unmitigated danger for resolving the situation in Donbass. Russia will continue its aggressive actions."

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.

The countries signed agreements regarding military transport and joint patrols on the 650-kilometer (406-mile) land, river and sea border between the countries.

Poroshenko later had lunch with Prime Minister Dacian Ciolos, who urged that Ukraine keep implementing reforms. Romania supports Ukraine's bid to join the 28-nation European Union.