UNITED NATIONS (Reuters) - A build-up of Russian military on Ukraine’s border with the Crimean region, which has been annexed by Moscow, could reflect “very bad intentions,” Ukraine’s U.N. envoy warned on Thursday after the U.N. Security Council discussed the growing tensions.

Ukrainian U.N. Ambassador Volodymyr Yelchenko, who requested the closed-door meeting of the 15-member council, said Russia had amassed more than 40,000 troops in Crimea, seized by Moscow in 2014, and on the Ukrainian border.

“These numbers may reflect some very bad intentions and this is the last thing we would like to happen,” he told reporters.

“My biggest hope is that this discussion (in the council) will help the Russian Federation to understand that they cannot really continue with this kind of behavior,” Yelchenko said.

Russian President Vladimir Putin has pledged to take counter-measures against Ukraine which he accused of sending saboteurs into Crimea to carry out terrorist acts.

Yelchenko called on Russia to produce proof of those accusations.

Russian U.N. Ambassador Vitaly Churkin dismissed concerns about a Russian military build-up. He described the Security Council meeting as “useful” to explain the situation.

“Instead of counting our military they should be bringing an end to the conflict in Donetsk and stop shelling civilians in Donetsk and Luhansk,” Churkin told reporters after the meeting.

Pro-Russian separatists are fighting the Kiev government’s forces in the eastern Ukraine region despite a fragile ceasefire. Civilian casualties from shelling, mines and booby traps in eastern Ukraine are at their highest in a year, the United Nations’ human rights chief has said.

A peace plan for the eastern Donbass region of Ukraine, negotiated in Minsk between Ukraine and Russia by Germany and France some 18-month ago, has stalled for months.

“There is chaos in Kiev, they don’t know what to do about Donetsk,” Churkin said. “We call upon all those who have influence on Kiev to make sure that they do what they are supposed to do (under the Minsk agreement).”

The Security Council has discussed Ukraine dozens of times since Russia annexed Crimea in 2014, but has been deadlocked on the topic as Moscow is one of the body’s five veto powers.