The government of Canada issues travel warnings for Canadians so that people can stay safe when they travel abroad. The risk level "is based on an overall assessment of the current security situation in a country or region."
These guidelines are purely for informational purposes and it is to individuals to exercise their judgement in deciding which countries to travel.
TL;DR The following countries are deemed unsafe for travel by the government of Canada, labelled as either "Avoid all travel" or "Avoid non-essential travel."
The two more "serious" travel advisories are "Avoid all travel" and "Avoid non-essential travel." The former, as the name indicates, advises travellers to avoid those areas at all cost because there is "an extreme risk to your personal safety and security." Those in countries labelled "avoid all travel" should consider coming home if it is safe to do so.
"Avoid non-essential travel" is applied to countries with specific safety and security concerns. According to the government's website, "it is up to you to decide what 'non-essential travel' means, based on family or business requirements, knowledge of or familiarity with a country, territory or region, and other factors."
These are the countries deemed unsafe for travel by the government, categrorised by travel advisory. All information is quoted directly from the government advisory website to to ensure accuracy.
"Avoid non-essential travel to Burkina Faso due to the threat of terrorism."
"The security situation throughout the country is unpredictable, and there is a significant risk of terrorism, crime, inter-communal clashes, armed attacks and kidnappings."
Democratic Republic of Congo
"Avoid non-essential travel to the Democratic Republic of Congo (DRC) due to the current political and security situation."
"Avoid all travel to Niger, with the exception of the capital, Niamey, due to the risks of terrorism and kidnapping."
"The security situation is unpredictable. There is a threat of terrorist attacks, kidnapping and sectarian violence."
"Avoid non-essential travel to Chad, including the capital, N’Djamena, due to incidences of violent crime and the threat of terrorism."
"Avoid non-essential travel to Mauritania due to the threat of terrorism, particularly against Western interests."
"Avoid non-essential travel to Egypt due to the unpredictable security situation. This advisory does not apply to the Red Sea coastal resorts of Hurghada (and its surroundings) and Sharm el-Sheikh, nor to the area from Luxor to Aswan along the upper Nile, where you should exercise a high degree of caution."
"If you decide to travel to Egypt despite this advisory, plan your trip with a reputable Egyptian travel company or agency, as they are well informed of the security situation and can better plan accordingly."
"Avoid non-essential travel to Eritrea, with the exception of the capital, Asmara. Ongoing tension between Eritrea and neighbouring countries could degenerate into conflict at any time."
"Avoid all travel to Venezuela due to the significant level of violent crime, the unstable political and economic situations and the decline in basic living conditions, including shortages of medication, food staples, gasoline and water."
"Avoid all travel to Haiti due to civil unrest throughout the country. The security situation could further deteriorate quickly. You should consider leaving by commercial means while they are available, if you can do so safely."
"Avoid all travel to Afghanistan due to the unstable security situation, ongoing insurgency, terrorist attacks, risk of kidnapping and high crime rate. If you choose to travel to Afghanistan despite this warning, you’re taking a serious risk."
"If you’re already in Afghanistan, you should leave. The ability of the Embassy of Canada to Afghanistan to provide consular and other support is very limited throughout the country."
"Avoid all travel to Somalia. If you are currently in Somalia despite this advisory, you should leave immediately."
"The security situation in Somalia is extremely volatile and the threat of domestic terrorism is high, particularly in south-central Somalia and in the capital, Mogadishu."
"Avoid all travel to Mali (including the capital, Bamako), due to the threat of terrorism and banditry. If the security situation in Mali deteriorates, the ability of the Embassy of Canada to Mali in Bamako to provide consular services may be limited."
"Avoid all travel to to South Sudan, due to armed conflicts, inter-ethnic violence and high levels of violent crime."
"Avoid all travel to to North Korea due to the uncertain security situation caused by its nuclear weapons development program and highly repressive regime."
"There is no resident Canadian government office in the country. The ability of Canadian officials to provide consular assistance in North Korea is extremely limited."
Central African Republic
"Avoid all travel to the Central African Republic due to unstable security conditions and violent crime."
"Avoid all travel to Burundi, due to ongoing political tensions, civil unrest and armed violence. The situation could deteriorate rapidly."
"Avoid all travel to Yemen, as the security situation has deteriorated significantly and foreigners are at extreme risk. Commercial means to exit the country are limited to departures from Aden and Seiyun. If you are currently in Yemen, seek safe shelter and remain there unless you can identify safe means of exit. The Government of Canada’s ability to provide any consular assistance in Yemen is extremely limited."
"Avoid all travel to Libya due to persistent insecurity throughout the country, including sustained armed conflict, a high risk of terrorist attacks, an unpredictable political situation and a high crime rate."
"Avoid all travel to Iraq, including the areas controlled by the Kurdistan Regional Government (KRG), due to a very volatile, dangerous and unpredictable security situation. If you are in Iraq, consider departing by commercial means if it is safe to do so."
"Avoid all travel to Syria due to ongoing conflict. Commercial means to leave Syria are extremely limited. Most commercial airlines have suspended their flights to and from Syria. Airports in Damascus and Aleppo may close quickly, with little or no notice, and checkpoints may delay or impede access to the airport."
"If you are in Syria, leave as soon as it is safe to do so. We have urged Canadians to leave Syria since November 2011."
If you are planning to travel to these countries, make sure to be very careful. Check the government's travel advisory website on a regular basis and inform yourself on the steps you need to take to stay safe.