Four boats carrying migrants have landed at the RAF air base at Akrotiri in Cyprus, the Ministry of Defence has confirmed.
It is believed to be the first time during the current migrant crisis in the Mediterranean that migrants have made landfall on UK sovereign territory.
The base has been used for bombing missions against the Islamic State terror group in Iraq.
No details were immediately available about where the 140 occupants of the boats – who include children – had set sail from or what nationalities they are.
European Commission president Jean-Claude Juncker has called a special summit of EU and Balkan leaders in Brussels on October 25 to discuss the migrant crisis.
Nations invited to attend are Austria, Bulgaria, Croatia, Macedonia, Germany, Greece, Hungary, Romania, Serbia and Slovenia.
The emergency meeting was called as Slovenia struggled to cope with a surge of migrants, after Hungary completed a razor-wire fence sealing its border with Croatia.
Slovenia’s interior ministry said Croatian authorities were dumping thousands of people a day at its southern border.
More than 600,000 migrants have arrived in the EU by boat over the course of 2015 – around 475,000 landing in Greece and 137,000 in Italy – according to figures from the International Organisation for Migration.
The majority of those arriving in Europe are believed to be from Syria, Afghanistan and Eritrea.
Despite its proximity to the Syrian coast around 100 miles across the sea, Cyprus has received relatively few migrants in the current crisis.