On Friday Jan. 27, citing terrorism concerns, President Trump issued an executive order that temporarily restricts entry to the U.S. from seven Muslim-majority countries. .
The United Nations has said 250,000 people have died in the conflict that grew out of protests against the rule of President Bashar al-Assad in 2011. Assad now holds the upper hand in the Syrian war, bolstered by allies Russia and Iran whose military involvement has turned the conflict to his advantage.
Above: A wounded youth is aided following an air strike on a rebel-held neighborhood of Aleppo on Apr. 26, 2016.
Syrian pro-government forces drive past residents fleeing eastern Aleppo on Nov. 30.
At the end of 2016, rebel groups were driven from areas they held for years in east Aleppo, their last major urban stronghold, causing a mass exodus of terrified civilians.
Syrian children wait for other members of their family after they crossed into Turkey near Hatay on Dec. 17, 2016.
Civilians have been fleeing Mosul in massive numbers as American-backed forces in Iraq have been battling for more than three months to recapture the ISIS stronghold. Humanitarian groups have warned that there are still hundreds of thousands of people in the besieged area facing severe food, water, fuel and medical shortages.
Above: Families displaced by the ongoing operation by Iraqi forces against ISIS in Mosul, gather in an area near Qayyarah on Oct. 24, 2016.
An Iraqi special forces soldier screams during a battle against ISIS fighters in Mosul's al-Rifaq neighborhood on Jan. 8, 2017.
A displaced Iraqi boy leads his animals to safety after escaping from the ISIS-controlled village of Abu Jarboa, near Mosul, on Nov. 1, 2016.
In 2015, Iran reached a landmark deal with six world powers aiming at curbing Iran's nuclear activities in exchange for easing international sanctions. Donald Trump has called the deal "catastrophic" and vowed to scrap it.
Above: Iranians celebrate after Iran's nuclear agreement with world powers was announced, in northern Tehran on Apr. 2, 2015.
An Iranian Shiite Muslim mourns after covering herself with mud during Ashoura rituals at the city of Khorramabad on Oct. 12, 2016.
Mourners chant slogans while flashing the victory sign, referring to the success of moderates and reformists in recent elections, during the funeral of former Iranian President Akbar Hashemi Rafsanjani, in Tehran on Jan. 10, 2017.
The al-Shabab extremist group, Al-Qaida's East African affiliate, is fighting to impose a strict version of Islam in Somalia, lashing out with deadly attacks like the assault on a hotel in the capital, Mogadishu, on Jan. 25, that killed at least 26.
Thousands of African Union troops are in Somalia to bolster the country's weak government.
Above: Rescuers carry an injured man from the scene of an explosion in front of Dayah hotel in Somalia's capital Mogadishu on Jan. 25, 2017.
Security forces patrol along the coast of Qaw, in Puntland on Dec. 18, 2016.
Armed militants groups have become more active in the Puntland's region, northern Somalia, since being pushed out of their strongholds in southern Somalia by African Union forces and the Somali National Army.
A fisherman carries a sailfish on his head to the fish market in Hamarweyne near the port of Mogadishu on Apr. 4, 2016.
Both Libya and Tripoli itself are home to myriad armed groups with shifting and conflicting loyalties that have sought to fill the power vacuum created when long-time leader Muammar Gaddafi was killed in 2011.
In 2014, fighting between armed alliances backing opposing political factions resulted in rival governments being set up in the capital and the east.
Since March last year a third, U.N.-backed government has been trying to establish itself in Tripoli.
Above: Smoke rises from a destroyed neighborhood in Sirte as fighting continued between pro-Libyan government fighters and ISIS on Sept. 22, 2016.
A sniper from Misrata fires towards ISIS positions in Sirte on Sept. 21, 2016.
Migrants wait to be rescued by members of Proactiva Open Arms in the Mediterranean Sea, some 12 nautical miles north of Libya on Oct. 4, 2016.
The largest flow of modern African migration funnels through a single country — Libya.
Some arrive by choice, others by force. But Libya is the purgatory where most migrants prepare to face the deadliest stretch of the Mediterranean Sea.
Yemen has been enmeshed in a civil war between Shiite Houthi rebels fighting the government of President Abed Rabbo Mansour Hadi that erupted in March 2015.
Al Qaeda has capitalized on the resultant chaos and has increased its territory in the country.
Above: An elderly man stands among the rubble of the Alsonidar Group's water pump and pipe factory after it was hit by Saudi-led airstrikes in Sanaa on Sept. 22, 2016.
A malnourished child waits to receive treatment at a therapeutic feeding center in a hospital in Sanaa on Jan. 24, 2016.
Hunger among Yemen's children has reached an "all time high", with nearly 2.2 million in need of urgent care, the U.N. children's agency UNICEF said in December.
At least 462,000 children suffer from severe acute malnutrition - meaning they are extremely underweight for their height - a drastic increase of almost 200 percent since 2014, UNICEF said.
A Yemeni Houthi supporter visits a cemetery in Sanaa on Mar. 25, 2016.
The UN says civilians account for more than half of the people killed in the conflict.
The U.S. has labelled Sudan a state sponsor of terrorism and enforces sanctions tied to Khartoum's role in the conflict in Darfur, where the United Nations says up to 300,000 people have been killed and millions displaced since 2003.
Above: Women walk past U.N. peacekeepers standing guard at the Attash refugee camp in Nyala in south Darfur on Jan. 9, 2017.
A Sudanese woman fills her ballot at a polling station on the first day of Sudan's presidential and legislative elections, in Izba, an impoverished neighborhood on the outskirts of Khartoum, on Apr. 13, 2015.