The World Health Organization (WHO) has called a meeting of members for Wednesday to discuss strategies to counter a new, more infectious variant of the coronavirus that has emerged in Britain.
A spokeswoman said the meeting was designed to help with information-sharing.
"Limiting travel to contain spread is prudent until we have better info," Hans Kluge, the WHO's Regional Director for Europe, tweeted.
However, the Geneva-based body has cautioned against major alarm over the variant, saying it is a normal part of a pandemic's evolution and praising Britain for detecting it.
As trucks barred from entering France backed up along miles of motorway in southern England, the WHO also said in a statement that cargo transport for essential supplies such as food, medicines and fuel should be prioritised and facilitated.
"Supply chains for essential goods & essential travel should remain possible," Kluge tweeted.
Drug makers including BioNTech and Moderna are scrambling to test their Covid-19 vaccines against the new variant.
The WHO repeated that there was not yet enough information to determine whether the new variant could affect vaccine efficacy.