The leadership of the self-proclaimed Donetsk People's Republic in Ukraine has begun unification talks the rebel-controlled Luhansk region, its representatives claim.

Activists from both Ukrainian regions, in which a referendum was held on Sunday for "self-government" with a purported "overwhelming" majority in favour, believe their territories should go hand in hand, according to Denis Pushilin, co-chair of the "People's Republic".

Pro-Russian protesters, who have retained control over government buildings across the east and south of Ukraine, consider their regions to be independent following the vote unrecognized by Kiev and the West, as they consider them "illegal".

Miroslav Rudenko, who also co-chairs the "Donetsk People's Republic", said it was "too early" to discuss incorporation into Russia.

"The first task is now to set ourselves free from the Nazi occupation of Kiev," Rudenko was quoted by ITAR-TASS as saying.

He was clear that the "Donetsk People's Republic does not need to be recognized by the International Community," citing previous examples as South Ossetia and Abkhazia, which only six states  say are independent. Kosovo, however, has been recognized by 100 countries, as Rudenko reminded.

Rudenko described the international community as "a US puppet", because "the US tell all the world who should be recognized and who should not".

The EU is meanwhile seeking another diplomatic push to solve the crisis.

Its Foreign Ministers approved on Monday the inclusion of 13 more Russian and Ukrainian citizens and 2 Crimean companies into a blacklist of sanctions imposed over the Ukraine crisis.

Among those with asset freezes and travel bans are President Putin's Deputy Chief of Staff, Vyacheslav Volodin, and Vyacheslav Ponomaryov, the self-proclaimed mayor of Slaviansk.

Two companies, Crimea's Chernomorsknaftegaz and Feodosia, were also in the list.

Canada has also announced measures against 12 more Russian and Ukrainian officials which, according to the Prime Minister Steven Harper, have facilitated the violation of sovereignty and territorial integrity of Ukraine. 

In a move showing support for the Ukrainian leadership, Germany's Foreign Minister Frank-Walter Steinmeier is to visit Kiev to explore the prospects for a national "round table" called with the mediation of the Organization for Security and Cooperation in Europe.