Royal Navy vessels are in the North Sea monitoring Russian warships thought to be heading to reinforce the attack on the besieged Syrian city Aleppo.
A Russian taskforce, including the aircraft carrier Admiral Kuznetsov, is on a course to sail through the North Sea to the English Channel, before heading for the eastern Mediterranean.
Type 45 destroyer HMS Duncan sailed from Portsmouth on Tuesday to “man-mark” the Kuznetsov group, which is heading south from the Norwegian Sea.
The Type 23 frigate HMS Richmond has escorted the group from the Norwegian Sea as it steamed south.
A Ministry of Defence spokesman said: “When these ships near our waters we will man-mark them every step of the way. We will be watching as part of our steadfast commitment to keep Britain safe.”
Syrian forces, backed by Russian air power, have agreed a humanitarian truce in Aleppo but Cabinet minister Priti Patel said the temporary truce was “woefully inadequate”.
The prospect of Russia’s only aircraft carrier heading to the region does not “inspire confidence” that Moscow is seeking a political solution to the Syrian conflict, Nato said.
A Nato official said: “Russia has the right to operate in international waters. There are plans in place for Nato navies to monitor the Russian ships as they head for the Mediterranean.
“At the same time, the deployment of the carrier group to the eastern Mediterranean does not inspire confidence that Russia is working towards a political solution to the conflict in Syria.”
Russian defence minister Sergei Shoigu said in September that the Admiral Kuznetsov-led Northern Fleet would be joining a taskforce in the Mediterranean.
According to the Russian news agency Tass, he told a defence board meeting that the plan was to bolster the Mediterranean fleet’s “combat capabilities”.
A statement from the fleet to the agency on October 15 said the group also consisted of the Pyotr Velikiy battlecruiser, the Severomorsk anti-submarine ship, the Vice-Admiral Kulakov destroyer and other support vessels.
The statement added: “Special focus will be made on safeguarding security of maritime traffic and other types of maritime economic activity of Russia and also on responding to the new kinds of modern threats such as piracy and international terrorism.”
Shadowing ships is regular business for the Royal Navy, with RAF surveillance aircraft also supporting the process on this occasion.
Navy ships will continue to escort the Russian task group and provide a visible presence south through the North Sea and English Channel as the Russian fleet sails through, the MoD said.
The UK is working alongside Nato partners to monitor the warships.
Vladimir Putin has held out the prospect of extending the cessation of bombing in Aleppo following a meeting with French president Francois Hollande and German chancellor Angela Merkel.
The Russian president said: “We informed them of our intention to continue, as much as possible, considering the situation on Syrian territory, a pause in the air strikes. We are ready to do this for as long as there are no clashes with rebel formations entrenched in Aleppo.”
International Development Secretary Ms Patel said: “A short pause in the onslaught against Aleppo is woefully inadequate. We need to see an end to the bombing and full access for aid agencies to the city.
“More than a quarter of a million civilians are still trapped in Aleppo. They are in a dire situation as they face regular bombing and severe shortages.
“Russia needs to allow full and sustained humanitarian access. It also needs to end its participation in the bombing. Any movement of people out of the city must be voluntary and overseen by independent monitors to ensure civilian protection.
“What is needed is a return to a full and lasting cessation of hostilities, including safe humanitarian access, across the whole country as well as in Aleppo.”
