The Ukraine and NATO on Monday launched 11 days of naval exercises, Sea Breeze 2010, despite the Ukraine's June decision not to join the defence alliance, DPA reported.
The manoeuvres had begun in the port city of Odessa, the Defence Ministry in Kiev said. NATO countries including Germany, the US, Poland and Georgia were taking part.
An anti-pirate exercise is to take place in the north-west of the Black Sea and a land exercise is to take place in the Nikolayev area.
Pro-Russian President Viktor Yanukovych had directed his Party of Regions not to block permission for the exercises in parliament.
But just last year, as leader of the opposition, he had spoken out against the manoeuvres.
The Ukraine's autonomous republic of Crimea, where the majority of the population is Russian-speaking, also passed a ban on the manoeuvres in its parliament last year.
The majority of Ukrainians are also against joining NATO, according to polls.
A small majority of the country's parliament in June approved a law put forward by Yanukovych confirming Ukraine's non-aligned status, thereby putting an end to the previous pro-Western government's quest for NATO membership.