Moscow has been accused of covering up a wider outbreak as health officials insist there is no transmission of the infectious disease and life has continued without disruption.

Mr Tsahkna told reporters at Estonia’s embassy in London on Wednesday that his country could “close the border within hours if there is need for that”.

“We have two border points,” he said. “We control every asset, every person, every car, everything which is crossing the border. We can close it very quickly.

“The readiness is always there. As a bordering country, we have a responsibility for Europe as well.”

Several non-European countries have already tightened their borders with Russia.

Kyrgyzstan ordered enhanced sanitary surveillance at every border crossing, Kazakhstan has implemented preventative measures at its border, and Uzbekistan has stepped up monitoring and screening protocols for incoming travellers.

The suspected plague death is being monitored closely by the US, which has already offered to provide support to Russia.

Marco Rubio, US Secretary of State, has urged Moscow to share “accurate information quickly and openly” as his department warned that many details remain unconfirmed.

Also keeping a keen eye on a potential outbreak is the World Health Organisation (WHO) – but the international body admitted it does not “have the full picture”.

The WHO said it was unable to “conduct a full risk assessment” because Russia did not provide enough information about the case, only sharing that no case of plague had been reported in the Irkutsk oblast and that 200 contacts were placed in quarantine.

Director-General of the World Health Organization Dr Tedros Adhanom Ghebreyesus said: “WHO has requested further information on the laboratory tests conducted on the individual who died and the contacts, more detail on what prompted the public health measures, and details about the health status of the contacts.

“We have also sought verification of media reports of a second employee with pneumonia of undetermined cause.

“WHO has offered technical support related to plague and laboratory biosafety and biosecurity.”

He added: “Timely, complete and transparent information sharing under the International Health Regulations is essential to clarify conflicting reports and enable an accurate assessment of potential public health risks.”

Meanwhile, in the US, Donald Trump and officials have downplayed the risk of a Covid-style outbreak.

The US Centre for Disease Control and Prevention (CDC) Director Erica Schwartz said her department is collaborating with a number of Government agencies to “understand exactly what that threat is”.

“We are very confident that the threat to the United States is extremely low,” she added.

On Wednesday, the President told reporters he did not believe Ms Shipilova’s death was caused by a bioweapon, adding that he now had a call set up with Vladimir Putin.

Russia remains steadfast in its claim that there is no risk of a global outbreak and cried that much of the concern was fake news.

Rospotrebnadzor, the country’s health watchdog, said it was winding down precautionary measures after concluding there was no risk of an epidemic.

When asked about the WHO’s assessment, Kremlin spokesman Dmitry Peskov said: “There is a great deal of media coverage, and the vast majority of what the media are reporting about this situation is false information.”

Russian Plague Outbreak Could Force European Union to Shut Borders ‘Within Hours’ Should Crisis Deepen

Reports of a potential plague-related health crisis linked to Russia have raised questions about how quickly European authorities could respond if a serious infectious disease threat began spreading across borders. The suggestion that the European Union could close its borders “within hours” has attracted attention, particularly amid continuing concerns about public health preparedness, international travel and the movement of people across Europe.

However, the prospect of an immediate, continent-wide border closure should be treated cautiously. Such a response would depend on the nature of the outbreak, the evidence of human-to-human transmission, the geographical spread of infections and assessments made by public-health authorities. A headline warning of an emergency does not, by itself, establish that EU borders are about to close.

Plague is a serious infectious disease caused by the bacterium Yersinia pestis. It is associated historically with devastating epidemics, but modern medicine can treat plague effectively with antibiotics when the disease is identified promptly. The risks vary according to the form of the disease and how people are exposed.

The central issue is therefore not simply whether a disease has been reported in Russia, but whether credible evidence indicates a threat that could spread internationally and require coordinated action.