Member states are urged to carry out a much more thorough assessment of each short-term visa application from Russian citizens.
The European Commission on Friday issued new guidelines to further tighten visa access for Russian citizens.
Home Affairs Commissioner Ylva Johansson said the new rules were in response to the security threat letting in a higher number of Russian citizens fleeing military conscription could pose and to the "serious situation" prompted by the illegal annexation by Russia of four Ukrainian regions and the reported attacks on two underwater pipelines.
She called on member states to conduct a "more thorough" security assessment of each short-term visa application and said that if there is any doubt the person intends to stay longer than the standard 90-day period or could pose a security threat, the visa should be refused
"We have heard Russian representatives talking about going to EU member states and using the same language as they used when they poisoned the Skripals, Yulia Skripal," she told reporters.
"We have also seen Russian citizens that have come with tourist visas with the aim to provoke Ukrainian refugees and to make propaganda for [Russian President Vladimir] Putin."
"I think the overall situation is that the security threat overall is much, much more serious. That means that we have to do much, much more thorough security assessments for each individual that we let into the EU from Russia," she added.
Some 66,000 Russian citizens legally entered the EU in the week following Putin's announcement of a partial mobilisation that could see up to 300,000 men conscripted to go fight in Ukraine, according to figures from Frontex, the bloc's external border agency. This is a 30% rise from the previous week.
Most of them arrived in Finland and Estonia, which both share land borders with Russia.
The majority of these legal entries concern people who either have dual citizenship or a residence permit or visas for a member state or the Schengen area.
The agency also said that it expects illegal border crossings to increase if Russia decides to close its borders to potential conscripts and that there could also be an increase in illegal stays in the EU by Russian citizens already present in member states.
According to Johansson, a lot of the Russian arrivals over the past week have been "men in the age for the mobilisation".
The Commissioner, who had previously announced the suspension of a visa facilitation agreement with Russia and restrictions on tourist visas for the country's citizens, also reiterated that member states are allowed to reassess already valid visas in the context of the security situation.
Russian citizens can still apply for long-stay visas as well as residence permits, including on humanitarian grounds with member states urged to prioritise urgent requests made by dissidents, independent journalists or for urgent family reasons.
Russians' right to demand asylum is also unchanged, per international law. That means that any Russian citizen that clearly states they intend to apply for asylum when they arrive at an EU border has to be let in, with or without a visa.
According to Johansson, there have been "around like 20 or 30 [asylum] applications per day" by Russian citizens over the past week.
For Russian citizens that have fled to third countries, including Georgia and Kazakhstan, and that go to European Union member states' consulates to apply for a visa, the Commission's recommendation is that authorities should be "very restrictive on issuing visas from third countries".
"Member States should not accept genuine visa applications from citizens of the Russian Federation that are present in a third country. They have to do that from their home country, Russia," she said.