The European Union on Monday slashed its estimate of the numbers of Russia troops along the Ukraine border from 150,000 to more than 100,000, correcting a statement earlier in the day.
But in the revised statement online, EU foreign policy chief Josep Borrell still warned that the Russian troop build-up was "very concerning," adding: "The risk of further escalation is evident."
Earlier, Borrell had said Russia had massed over 150,000 troops along the Ukrainian border and in the annexed Crimea peninsula, in comments to journalists following talks involving Ukraine's foreign minister.
But he refused to disclose the source of the figure.
In a statement put online on Monday evening, the figure quoted by Borrell had been revised down to "more than 100,000." A footnote explained that the figure had been corrected, but with no further explanation.
Tensions have spiraled over the build-up of Russian troops around its southwestern neighbor as an intensification of clashes with Moscow-backed separatists has fuelled fears of a return to widespread fighting in Ukraine.
Moscow's military says it is conducting exercises along its frontier in response to moves by Western military alliance NATO that "threaten Russia."
Defence Minister Sergei Shoigu said last week that "two armies and three airborne units were successfully deployed" to the Russia's western border and that the drills would be over "within two weeks."
Ukraine is pushing the West for more practical support as it looks to deter any further aggression from Moscow.
Kiev's Foreign Minister Dmytro Kuleba pressed the EU to prepare "a new set of sectoral sanctions" against Russia in talks with his counterparts from the 27-nation bloc on Monday.
But Borrell said that there were currently no further sanctions being proposed or under consideration.
The Russian build-up comes as clashes between Ukrainian forces and Moscow-backed separatists have flared in the east in recent weeks, shredding a ceasefire brokered last year.
A Ukrainian soldier was killed and one more wounded in the latest bloodshed in the conflict-ridden east, the military said Monday.
Kiev has been battling pro-Russian separatists in the eastern Donetsk and Lugansk regions since 2014, following Moscow's seizure of Crimea.
Talks between advisers to the heads of state of Ukraine, Russia, Germany and France — which have been negotiating over the conflict since 2015 — are scheduled to be held later on Monday in Kiev.
