BERLIN—The Netherlands and Belgium on Sunday banned flights from the UK and Germany considered limiting such flights in attempt to ensure that a new strain of coronavirus sweeping across southern England does not establish a strong foothold on the continent. The Netherlands banned flights from the UK for at least the rest of the year while Belgium issued a flight ban for 24 hours starting at midnight and also halted train links to Britain. German officials were considering “serious options” regarding incoming flights from the UK, but have not yet taken action. The Netherlands said it will assess “with other European Union nations the possibilities to contain the import of the virus from the United Kingdom.” The three EU governments say their response comes in reaction to tougher measures imposed Saturday in London and surrounding areas by British Prime Minister Boris Johnson. He immediately put those regions into a new …