European Union and NATO state Romania share a 650-kilometer (400-mile) border with Ukraine, is host to a US ballistic missile defense system, and, as of this year, has had a permanent alliance battlegroup stationed on its territory, Daily Hunt reported.
Some 2.65 million Ukrainians have fled to Europe through Romania in the eight months since the war started.
"My gesture (resignation) comes as it is impossible to cooperate with the Romanian president, the army's commander-in-chief," Dincu said in a statement.
"I think my withdrawal from the post is necessary so as to not harm decisions and programs which require fluid command chains and to not block a series of projects which are absolutely necessary. the ministry and the army."
In early October, Dincu said Ukraine needed international allies to negotiate security guarantees and peace with Russia, sparking criticism from President Klaus Iohannis and leaders of the ruling governing coalition.
He later said his comments were taken out of context. Iohannis said Ukrainians were paying with blood in the war and only they could decide what and when to negotiate, a position held by Romania and the EU.
RHM/PR