Pro-Russian separatists in Donetsk on May 12 have declared independence and asked Moscow to deploy Russian troops and consider absorbing the eastern Ukrainian region.
The annexation appeal came in a statement read out at a news conference by Denis Pushilin, a leading member of the self-declared "Donetsk People's Republic."
It came one day after Donetsk and the neighboring Luhansk region held so-called self-rule referendums fraught with problems
In the city of Slovyansk, which has been a flashpoint in the Donetsk region, the pro-Russian, self-styled "mayor," Vyacheslav Ponomaryov, called for Russian troops to provide stability and peace.
Ponomaryov described Ukrainian troops as occupiers.
Speaking in the administrative building in Slovyansk, the stronhgold of the armed rebels in eastern Ukraine, he said that Ukrainian soldiers "should go."
Asked whether the "Donetsk People's Republic" needed Russian military help, Ponomaryov replied: "I support this. We need Russian troops to provide stability and a peaceful life in the region's future."
The calls followed declarations by authorities in Donetsk and Luhansk of high voter turnout and overwhelming support for independence in the May 11 votes.
No international monitors observed the votes, and separatist gunmen manned polling stations.
Ukraine's government and Western states have rejected the processes as illegal.
The White House reiterated on May 12 that the referendums are illegal. Spokesman Jay Carney said Washington does not recognize the results.
U.S. State Department spokeswoman Jen Psaki said the voting "was an attempt to create further division and disorder in the country."
EU President Herman Van Rompuy, on a visit to Kyiv, said the European Union does recognize the processes, which he called "illegal, illegitimate, and not credible."
The European Union on May 12 expanded its sanctions against Russia over the Ukraine crisis.
Van Rompuy said the EU was prepared to take "additional, far-reaching steps" if Moscow failed to help resolve the conflict.
The Russian government said the results of the votes should be "implemented in a civilized manner" and urged Ukrainian officials in Kiyv to engage in talks with the separatists.
There was no immediate reaction from either Ukraine's government or Russia to Pushilin's statement.
Acting Ukrainian President Oleksandr Turchynov earlier on May 12 called the votes in Donetsk and Luhansk a "farce" without any legal basis.
WATCH: Ukraine's acting President Oleksandr Turchynov accused Russia of trying to overthrow legitimate state power in Ukraine after pro-Russian rebels claimed victory in a self-rule referendum in eastern regions:
Russian President Vladimir Putin's office in a statement said that "Moscow respects the expression of the people's will" in Donetsk and Luhansk.
Self-styled separatist officials in Donetsk said 89 percent of voters backed breaking away from Ukraine in their referendum, with a turnout of 75 percent.
Separatists in Luhansk said 96 percent of those who voted had backed independence.
The two industrial regions are home to almost 7 million of Ukraine's 46 million people.
The separatists also said that Ukraine's May 25 presidential election will not happen in the regions.
Russian Foreign Minister Sergei Lavrov said there was no further point in talks to resolve the Ukraine crisis without the separatists.
The European Union published its list of fresh sanctions targets over the Ukraine crisis -- 13 Russian and Crimean individuals and two companies
-- including: Vyacheslav Volodin, first deputy chief of staff to Russian President Vladimir Putin; Vladimir Shamanov, commander of the Russian Airborne Troops; Vladimir Pligin, head of the Russian Duma's Constitutional Law Committee; self-styled Slovyansk leader Ponomaryov; Crimean prosecutor Natalya Poklonskaya; and Pyotr Jarosh, acting head of the Federal Migration Service office for Crimea.
The 13 people bring to 61 the total number of individuals who will face EU travel bans and asset freezes.
The two Crimean companies, PJSC Chernomorneftegaz and Feodosia, were nationalized by Russia after it annexed Crimea earlier in March following a hastily arranged referendum there under Russian occupation.
EU foreign policy chief Catherine Ashton hinted that any disruption of Ukraine's May 25 presidential election could trigger new sanctions.
With reporting by Reuters, AP, AFP, and RT.com