Ukrainian President Petro Poroshenko has issued a decree instructing his government to consider temporarily closing the eastern border with Russia to help halt its "intervention" in the ex-Soviet state's affairs.
The decree published on the presidential website orders the government "to settle ... the issue of temporary closing checkpoints on Ukraine's state border with the Russian Federation to cars, sea and pedestrian traffic".
Mr Poroshenko's decree said it was issued "in connection with the continued intervention of the Russian Federation in Ukraine's internal affairs".
He also said he will present a plan later today for broad reforms that will allow Ukraine to apply for European Union membership "in six years' time".
Ukraine's parliament ratified a landmark association agreement with the EU on 16 September, though implementation of the trade part of the agreement has been delayed until January 2016 to appease Russia, which said the pact will hurt its markets.
Mr Poroshenko, speaking to the country's judiciary, also said that for the first time in many months no deaths or wounded had been reported in the past 24 hours in the conflict with pro-Russian separatists in eastern Ukraine, indicating that a ceasefire "has finally begun working".
It comes as Ukrainian Prime Minister Areseniy Yatsenyuk asked member states of the United Nations to live up to the organisation's charter.
Speaking at the end of the day to an almost empty hall of the 193-nation assembly, the prime minister described the actions of their larger neighbour, saying it had "just decided to grab the land of an independent Ukraine".
He said the Russian Federation violated a number of bilateral and multilateral international agreements "starting with the UN charter and ending with the resolutions on counter-terrorism that were passed by the UN. So we know what terrorism means".
Mr Yatsenyuk pushed for a diplomatic solution.
He said: "We urge Russia to pull back its forces, to pull back its artillery, to stop the supply of Russian-led terrorists, to restore the control over Ukrainian-Russian border, and to start real talks. Peace talks.
"We are the country that needs peace and it's difficult to hammer out any kind of peace deal at the barrel of a gun . . . made in Russia."
He went on to ask for continued support from the international community before reaffirming Crimea as part of his country.
Mr Yatsenyuk said: "We ask our partners not to lift sanctions until Ukraine takes over the control of its entire territory, starting with the east of Ukraine and ending with Crimea. Crimea was, is, and will be a part of Ukraine.
"Mr Putin, you can win the fight against the troops, but you will never win the fight against the nation, united Ukrainian nation."
Though nothing significant is expected from the meeting in New York, more than 140 heads of state or government are attending the annual general debate, which ends on 30 September.
