"March 16 and May 9 are the days on which Russia traditionally attempts to discredit our country," Mežviets said,
"This year the risks posed will certainly be higher."
March 16 is the day on which an unofficial but large parade takes place in central Riga commemorating the Latvian Legion, divisions of the Waffen SS that fought on the Nazi side in World War Two.
May 9 is the day on which first the Soviet Union and now Russia celebrates victory over Nazi Germany in World War Two and sees tens of thousands of Latvia's Russian community converging on a Soviet War memorial in a Riga park to lay flowers and celebrate.
Caught between two superpowers, around 140,000 Latvians fought on each side after inter-war independence was crushed by the infamous Molotov-Ribbentrop pact.
Both dates will be given extra significance by the fact that Latvia will hold the rotating presidency of the European Union when they occur, raising the possibility that headline-seeking provocateurs may use them for their own purposes.
In addition, the direction that events take in Ukraine is also likely to influence the mood of both events, Mežviets said, with more than 30 new security officers already recruited as a direct result of events so far.
"This will be a very serious and significant period for our country which is why the Security Police must ensure we are ready for any eventuality in order to ensure national security," Mežviets said.
"Foreign security services may attempt to spread disinformation about us during the presidency of the European Union... we need to be ready to counter disinformation campaigns against our country."
"Naturally, senior officials have been informed about the risks that might be posed."
"Of course of the most serious security threats to our national security interests is posed by pro-Russian nationalist politicians," Mežviets said, explaining that the purpose of such activities was to divide society and encourage Latvia's Russians to feel loyal towards Moscow rather than their own country.
However, he also stressed that Latvia as a rule-of-law based republic had an obligation to let people voice dissent via legal channels.
Recent years have seen a massive police presence on both dates ensuring public order apart from a few minor incidents.
In 2014, NA minister Einars Cilinskis was dismissed after he ignored a ban from Prime Minister Laimdota Straujuma on attendance at the March 1 event, but it remains to be seen if a similar ban on ministerial participation will be applied next year.
Mežviets was installed as DP boss on November 8, replacing long-time DP chief Janis Reiniks.
"I have already been working at DP for ten years... I feel I have the support of my colleagues," Mežviets said.