The Royal Navy's HMS Diamond has finally set sail from Portsmouth to join NATO allies in the eastern Mediterranean.
The Type 45 destroyer will first take part in sea trials before heading to the region where HMS Trent, a River-class offshore patrol vessel, has been conducting patrols with other alliance members.
The UK increased its contribution to NATO defences last week, prior to Russia's attack on Ukraine.
HMS Diamond had been expected to set sail from Portsmouth last week, with her departure initially delayed due to Storm Eunice.
Then on Monday, the Navy said the Type 45 destroyer required "minor repair" but was expected to leave soon.
But HMS Diamond was again unable to set sail on Wednesday morning as expected because of a "technical issue".
The Type 45 destroyer returned to the UK in December after being part of the Carrier Strike Group 21 mission – a deployment during which the destroyer suffered several "technical issues".
Watch: HMS Diamond and HMS Defender return from CSG21.
Britain said last week it is doubling the number of troops in Estonia, with about 850 members of The Royal Welsh battlegroup heading from bases in the UK and Germany to the Baltic nation.
Most of the 350 Royal Marines who deployed to Poland this month have already arrived according to the Ministry of Defence, with 1,000 extra British personnel at readiness in the UK if needed.
Four additional RAF Typhoon jets headed to Cyprus to join NATO patrols over eastern Europe.