Miroslav Rudenko, one of the political officials of the Donetsk People's Republic, which held a referendum on independence Sunday in some parts of the Donetsk region, said the rebels will now set about subordinating all the power structures in the region to the leaders of the self-declared people's republic and cutting off ties with authorities in Kiev.
The moves come as the Kremlin said in a statement Monday that it viewed the referendum in Ukraine's east "with respect" and expressed hope for a civilized implementation of the results.
"This is great news, very happy news. Excellent, excellent," Mr. Rudenko said in response to the Kremlin's statement, which rebels in Ukraine's southeast see as a sign of support.
Ukrainian, European and U.S. officials have denounced the referendum as illegal.
Kiev has described the pro-Russia rebels as terrorists and launched a military operation with the hopes of expelling them from towns they have seized.
Clashes have resulted in a number of deaths across southeast Ukraine.
Mr. Rudenko described as unlikely the Crimea scenario -- where Russia quickly followed up a popular referendum with annexation -- and said the Donetsk People's Republic therefore would take steps to develop as a sovereign state.
Those include "integration steps" such as joining a Kremlin-run customs union with former Soviet republics and building relations with the neighboring Luhansk People's Republic, he said.
Rebels in the neighboring region of Luhansk also held a referendum on independence Sunday.
Mr. Rudenko said the Donetsk People's Republic would also step up moves to protect the Donetsk region from police and military loyal to Kiev.
"They never had any moral right to attack us," Mr. Rudenko said.
"Now, after the referendum, they don't have a legal right for their aggression against an independent state... They are occupiers."
Echoing the Kremlin, Mr. Rudenko expressed hope for a political resolution to the confrontation with Kiev -- likely some sort of federalized structure that would devote more powers to the Donetsk region.
Kiev has suggested that such an arrangement would essentially establish a Kremlin proxy state within Ukraine that would destabilize the already-fragile government.
Without a political resolution, Mr. Rudenko said forces loyal to the people's republic would take up arms and defend themselves.
Source: The Wall Street Journal