BRUSSELS (Reuters) - NATO members are set to take tougher action against Russian spies across the alliance in response to a campaign of hostile activities by Moscow that includes acts of sabotage and cyber attacks, NATO chief Jens Stoltenberg said on Thursday.

"We have seen several examples of sabotage, of arson attempts, of cyber attacks, of disinformation," he told reporters, adding NATO defence ministers meeting in Brussels later in the day would "address the Russian campaign of hostile activities against NATO allies".

Stoltenberg said ministers would also discuss NATO's options to respond, including the protection of critical maritime and cyber infrastructure, and also "tighter restrictions on Russian intelligence personnel across the alliance".

(Reporting by Sabine Siebold and Bart Meijer)