Speaking ahead of his attendance at a major NATO summit in Wales on September 4-5, Vejonis said he had called a press conference because there were so many questions in the air at the moment they needed to be addressed.
Vejonis began with a prediction that the Ukrainian army was moving towards a "decisive victory" in the country's breakaway regions but warned that Moscow might find "new mechanisms to reinforce the separatists".
He also cautioned against a "wide-ranging propaganda war in the media" that was trying to persuade people that NATO would not take seriously its Article 5 commitment to defend all members from attack, that Latvia was completely dependent upon Russia for its economic well-being and that sanctions might be used as an excuse to foment political unrest.
Vejonis commented on large scale military exercises currently taking place just across the border near Pskov in Russia as just the latest in a series of aggressive actions by Russia.
Every time there's an unidentified craft, whether it is a boat or a plane, we have the capability to make an appropriate response"
"In recent times we have seen various classes of boats venturing into neutral waters, including warships and submarines... every time there's an unidentified craft, whether it is a boat or a plane, we have the capability to make an appropriate response," he said.
He also lamented Russian snap exercises taking place near Pskov that appeared to simulate an invasion of the Baltic states.
"3,000 Russian troops are training to invade and seize objects in an unnamed territory," Vejonis said.
"This scenario shows Russia wants to present itself as strong and as an aggressor, but with these and various other exercises also taking place in other parts of Russia it's sad, in my opinion, that Russians are being asked to pay for them because such large-scale exercises cost an awful lot of money whether you are paying in euros, dollars or roubles."
On the subject of whether Latvia and the other Baltic states needed permanent bases manned by troops from other NATO member states in addition to local armed forces, he said a range of options about how to "reinforce NATO's military strength" were on the table for discussion in Wales including permanent bases and the rotation of forces throughout various countries in Eastern Europe.
"Whether it's bases or rotation, we will discuss and decide accordingly," Vejonis said, adding that Latvia would itself be hosting five different military training exercises in coming months that will see a range of hi-tech military hardware landing on Baltic shores including Apache helicopters and M-1 Abrams tanks from the US.