NATO's deputy chief vowed Monday to strengthen the alliance's partnership with Moldova during a visit in the former Soviet country that could inflame tensions with Moscow.

NATO's deputy secretary general Alexander Vershbow wrote on Twitter the alliance is "committed to enhance partnership (with) Moldova in full respect of its neutrality, supporting its independence, integrity and sovereignty."

But in a remark aimed at appeasing Moscow after Moldovan President Nicolae Timofti and other top officials, he added that the partnership is "not exclusive or competitive" and one can remain a "strong friend of Russia" and still be a member.

The visit comes after Russian Deputy Prime Minister Dmitry Rogozin enraged Chisinau over the weekend by delivering boxes of petitions asking Russia to recognize Moldova's breakaway Transdniestr region to Moscow.

Russia's annexation of Crimea from Ukraine in March has prompted fears it could claim other disputed ex-Soviet regions with majority Russian-speaking populations.

Moldova's government slammed Rogozin's "unproductive" acts and "provocative statements on Moldova", saying they "do not help to make progress in the Transdniestr conflict".

In an interview to Radio Free Europe, Vershbow, a longtime former envoy to Moscow, expressed concern the Ukraine crisis could impact Moldova and warned that NATO views any attempts to stir separatism "very negatively".

Russia's Rogozin hit back, saying that Russia could send more troops to Transdniestr, a thin strip of land wedged between the Dniestr river and the border with Ukraine.

In an interview with daily Kommersant published on Monday, the hawkish Rogozin condemned Moldova's increased cooperation with the West and said Russian soldiers could "absolutely" appear in Transdniestr if it is in "physical danger".

"We see what is going on next to it in (Ukraine's) Odessa region," Rogozin said, claiming there are violent "idiots" there who want to "meddle in Transdniestr."

A clash between pro-Ukrainian and pro-Russian supporters in Odessa earlier this month led to a blaze that claimed 42 lives, mostly people opposing authorities in Kiev.

Rogozin, who oversees Russia's military industrial complex and has been blacklisted by the European Union over involvement in the Ukraine crisis, promised Transdniestr on his visit that Moscow will ensure its security.

He flaunted his support of the separatists, overseeing a Victory Day parade on May 9 and posting pictures of himself fishing on the Dniestr river.