President Petro Poroshenko said Tuesday that Ukraine's membership in NATO remained a "strategic goal" even though the Western military alliance remained skeptical about enlisting the former Soviet state.
The pro-Western leader's comments are sure to irritate Russia at a time when the neighbors' relations are already boiling over Moscow's allegations that Kiev tried to seize back the Kremlin-annexed Crimea peninsula last month.
Poroshenko told lawmakers at the start of Ukraine's new parliament session that Kiev had already achieved "an unprecedented and very close level of cooperation with Alliance member states."
"Our strategic goal is NATO membership," he said. "I would like to stress that this is an unwavering course -- like the Northern Star in the sky."
Poroshenko has also set his sights set on applying for European Union membership by 2020 since taking over from ousted Moscow-backed president Viktor Yanukovych in the wake Ukraine's February 2014 pro-EU revolt.
Some NATO member states have expressed concern that Ukraine's accession would only further infuriate Moscow.
Russian President Vladimir Putin denies backing the 28-month pro-Moscow insurgency in eastern Ukraine that has claimed nearly 10,000 lives.
But he admits that his soldiers swarmed the strategic Black Sea peninsula before Crimea's formal annexation in March 2014 followed a local referendum that the UN General Assembly nearly unanimously called "illegal".
Putin also concedes that some Russians have voluntarily "followed their heart's call" and fought alongside the pro-Moscow militia against Ukrainian government troops.
The Kremlin chief further feels threatened by NATO's decision to set up battalions that would protect east European nations from any possible Russian military moves into countries run by the Kremlin during Soviet times.
Ukraine conducts regular joint military exercises with NATO but remains frustrated that the Alliance refuses to supply it with offensive military equipment that could help it ward off what it views as Russia's invasion of its industrial east.
NATO members also say Ukraine's recently-upgraded army still remains far off the standards required for membership.
Poroshenko has not set a target date for submitting his country's application to join NATO.
He has previously promised to hold a national referendum on the subject before his first term runs out in 2019 -- a plebiscite Poroshenko is confident he will win.
A poll conducted by Kiev's International Institute of Sociology between May 20 and June 2 showed 43.9 percent of the respondents favouring Ukraine's membership in the bloc.
Another 38 percent were against the idea, while 18.1 percent remained undecided.
Studies show that slightly more than 20 percent of the population supported Ukraine becoming a NATO member while Yanukovych was in power in 2013.
Poroshenko said in his appeal that "Ukraine requires further serious international support in its fight against Russia's aggression."
There was no immediate response to his comments from Moscow.