Ukrainian President Petro Poroshenko meets his security chiefs on November 4.
They are due to discuss the government's commitments to a September 5 truce after controversial elections in the east by pro-Russian separatists.
Poroshenko said the vote in rebel-held areas of Luhansk and Donetsk on November 2 had violated terms of the Minsk cease-fire agreement.
Calling the elections a "farce," Poroshenko said he intended to scrap a law granting limited autonomy to the two mainly Russian speaking areas.
In Washington, the White House said it will not recognize the "sham" elections held by the separatists, echoing earlier condemnation by the European Union.
Bernadette Meeham, spokesperson for the White House National Security Council, also expressed concern that Moscow was trying to legitimize the results.
A Russian deputy foreign minister, Grigory Karasin, earlier said the newly elected leadership in eastern Ukraine now had a mandate to negotiate with Kyiv.
The spokesman for German Chancellor Angela Merkel said Germany could not understand how "official Russian voices" were talking of recognizing the elections.
The head of the election body in Donetsk, Roman Lyagin, said inescapable conclusions needed to be drawn from the polls.
"Kyiv has to come to terms with the idea that Donbas is not part of Ukraine," Lyagin said.
Rebel commander Alexander Zakharchenko won 81 percent of the vote in the so-called Donetsk People's Republic, while Igor Plotnitsky was elected president in Luhansk with 63 percent.
The Ukrainian government warned on November 3 that more Russian soldiers and armored vehicles were being deployed in the separatist-controlled areas in Donetsk and Luhansk.
"The presence of Russian troops is not even being disguised," Ukrainian security spokesman Andriy Lysenko said.
NATO's top military commander, U.S. Air Force General Philip Breedlove, said Russia continues to resupply the pro-Moscow separatists in Ukraine, and estimated that some 250-300 Russian forces are still operating inside Ukraine.
Breedlove noted what he called a trend toward the hardening of the line of demarcation between Ukrainian government forces and the separatists, saying it "has become more defined."
At the same time, he said, the border between Ukraine and Russia has become "completely porous," allowing for the unhindered movement by the pro-Russian forces.
With reporting by Reuters and AP