NATO Secretary-General Jens Stoltenberg says he is "concerned" that a Russian aircraft carrier and its task force that is heading to the eastern Mediterranean Sea will join Russian attacks on the Syrian city of Aleppo and "increase human suffering."
Stoltenberg said on October 20 that navies from NATO member states would monitor the movements of the Russian task force in a "responsible and measured way."
The Russian Navy deployment would increase its firepower in Syria, where it has been carrying out air strikes in support of President Bashar al-Assad's army for more than a year.
The Admiral Kuznetsov, Russia’s only aircraft carrier, can carry dozens of fighter bombers.
It is accompanied by a nuclear-powered battle cruiser, two antisubmarine warships, and four support vessels.
The deployment comes amid an offensive by Assad's troops on rebel-held neighborhoods of Aleppo, backed by Russian warplanes, that has caused international outrage.
It also comes amid heightened tensions between Moscow and NATO, which has accused Russia of provocative military maneuvers.
The British Navy was shadowing the Admiral Kuznetsov and seven other Russian warships on their journey from the Norwegian Sea to the North Sea and through the English Channel as they head toward Syria.
Admiral Vyacheslav Popov, the former commander of Russia's Northern Fleet, says the task force could cover the distance from the English Channel to the eastern Mediterranean in "less than a week" at top speed.
He said that at "medium speed, it can take up to two weeks."
British Defense Secretary Michael Fallon said on October 19: "When these ships near our waters, we will man-mark them every step of the way" and will be watching them "as part of our steadfast commitment to keep Britain safe."
British Prime Minister Theresa May has urged the European Union to unite in condemning Russia's role in Syria and bring an end to what she called Moscow's "sickening atrocities" there.
Meanwhile, momentum was building among EU leaders for sanctions against supporters of Assad's regime -- including Russia -- if they fail to stop atrocities in Syria.
A draft statement obtained by RFE/RL at an EU summit in Brussels on October 20 said the bloc was "considering all options, including further restrictive measures targeting individuals and entities supporting the [Syrian] regime, should the current atrocities continue."
Russia was not specifically named in the threat of more punitive measures, but was singled out in the draft statement -- which said the EU "strongly condemns the attacks by the Syrian regime and its allies, notably Russia, on civilians in Aleppo."
Russia announced on October 20 that it would pause its air strikes for 11 hours each day for the next four days to allow civilians to leave Aleppo and aid workers to deliver humanitarian supplies.
But officials at the EU summit dismissed the gesture as being timed to coincide with their talks in Brussels in an attempt to minimize the growing momentum toward sanctions against Russia.
During the break in fighting in Aleppo on October 20, Syria's military used loudspeakers to call on residents to evacuate.
However. there was no sign of such a move among the estimated 250,000 civilians trapped in the besieged city's rebel-held eastern district.
With reporting by Reuters, AP, BBC, and The Telegraph