Moldova's President Igor Dodon is facing a backlash from political opponents and civil society activists after announcing that he intends to accompany Russian Deputy Prime Minister Dmitry Rogozin to the breakaway region of Transnistria and decorate Russian peacekeepers on the 25th anniversary of their deployment later this week.

Dodon, who has repeatedly been criticised for his pro-Russian stance and closeness to the Russian-backed Transnistrian separatists, intends on Friday to award Moldovan state honours to both the Russian peacekeepers and Transnistrian soldiers.

Parliament speaker and ruling Democratic Party member Andrian Candu said that Dodon will violate Moldova's constitution if he proceeds with the ceremony as planned.

"Dodon is confusing state distinctions with protocol presents," Candu wrote on Facebook.

"Mr. Dodon, don't make us believe that the head of state has too many prerogatives," he added.

Former presidential candidate Maia Sandu also criticised Dodon for colluding with Rogozin, who called Moldovans and Romanians fascists in a book that he published in 2008.

"[In order for the Russians to stay in Transnistria, Dodon] is willing to offer a handful of medals to those who shot our volunteers in 1992 and we do not rule out that he will find a distinction for Rogozin, who did the same," Sandu wrote on Facebook.

In his book 'Vrag Naroda' ('Enemy of the People'), Rogozin wrote that in 1992, he gathered volunteers in Moscow and travelled to fight against the Moldovan military in the Transnistrian war.

Dodon announced last week that he will receive Rogozin, despite a letter from the Moldovan government warning the Russian deputy premier not to arrive in Moldova with a military plane and a delegation.