"Goodbye smartphone," former Foreign Minister Martin Lidegaard of the Social Liberal Party said in a post on Facebook.
"On the way to Russia with the Foreign Policy Committee, where we have been advised not to bring gadgets for the sake of safety," Lidegaard wrote.
During his time as foreign minister, Lidegaard said the European Union should prepare for more hybrid warfare from Russia.
Nick Haekkerup of the Social Democrats, Denmark's main opposition party, said on Facebook he would have to manage without internet, mails and social media for a week
"I'm travelling with the Foreign Policy Committee and have for security reasons been asked to leave everything like iPhone, iPad or similar at home," Haekkerup said.
Danish ministries have been attacked several times in 2015 and 2016 by a foreign, state-sponsored hacking group, a cyber security unit within the defence ministry said in a February report.
The unit declined to specify which country had sponsored the hacking group but said in the report that Russia and China have extensive capabilities to carry out cyber espionage.
The threat from cyber crime against Danish authorities and companies continues to be "very high", according to the report.
US intelligence agencies concluded last year that Russia hacked and leaked Democrat emails during the 2016 presidential election campaign as part of an effort to tilt the vote in Republican Donald Trump's favor. Russia has denied the allegations.
Danish authorities did not immediately respond to Reuters' requests for further information.
Reporting by Teis Jensen and Stine Jacobsen, Additional reporting by Nikolaj Skydsgaard, Editing by Angus MacSwan