The U.S.-led international force formally ended its 13-year combat mission in Afghanistan during the bloodiest year of the war, the longest in American history.

“The road before us remains challenging, but we will triumph,” said Gen. John Campbell, the top commander of U.S. and NATO troops in Afghanistan, in a quiet symbolic ceremony on Sunday that marked the transition of the mission from combat to train and support.

“We have lifted the Afghan people out of the darkness of despair and given them hope for the future,” he added.

President Obama marked the end of the combat mission in Afghanistan, releasing a statement from Hawaii where he is vacationing with his family, arguing that the U.S. is more secure now.

“Thanks to the extraordinary sacrifices of our men and women in uniform, our combat mission in Afghanistan is  ending, and the longest war in American history is coming to a responsible conclusion,” said the president. “We are safer, and our nation is more secure, because of their service.”

During the ceremony in Afghanistan, Gen. Campbell rolled up and sheathed the green and white International Security Assistance Force (ISAF) flag and unfurled the flag of the new mission dubbed Resolute Support.

“There is a need for continued support, and that’s going to be given in Resolute Support,” German Army Lt. Gen. Carsten Jacobson, the coalition’s deputy commander, told The Wall Street Journal (WSJ) in an interview ahead of the ceremony. “But we are not here in a fire-brigade role that intervenes and takes over the fight, as we’ve done in previous years.”

The ceremony took place Sunday afternoon away from the public, at a basketball court inside ISAF’s headquarters in the Afghanistan capital of Kabul, which has been at the center of a surge in Taliban attacks across the country this year.

“Fearing Taliban attacks, the base was on high alert,” reports WSJ. “Nonresident staff was told to stay home, and facilities like shops and coffee bars were closed for the day.”

Taliban spokesman Zabihullah Mujahid referred to the event as a “defeat ceremony,” adding that insurgents will continue to fight.

“Since the invasion in 2001 until now, these events have been aimed at changing public opinion, but we will fight until there is not one foreign soldier on Afghan soil and we have established an Islamic state,” the spokesman said, reports The Associated Press.

President Obama expanded the post-2014 role of the U.S. troops, allowing them to conduct counter-terrorism operations against al-Qaeda and the Taliban for at least the next two years.

According to official Afghan government data obtained by The New York Times, more than 5,000 Afghan soldiers and police have been killed in 2014, more than in any other year since the war began on Oct. 7, 2001.

The Afghan deaths are more than twice the 2,213 American soldiers who, according to an AP tally, have been killed throughout the 13-year old war.

Afghan fatalities this year also exceed the war’s estimated 3,500 coalition deaths, a figure that includes American fatalities.

“We honor coalition and Afghan fallen in this mighty struggle, those who paid the price for Afghanistan’s freedom,” said Gen. Campbell during the ceremony.

Last week, the United Nations predicted that civilian casualties in Afghanistan will surpass 10,000 in 2014, eclipsing all other years since the U.N. began its authoritative reports in 2009. Taliban jihadists were responsible for the majority of civilian deaths and injuries, the U.N. revealed.

According to the AP tally, there have been at least 42 U.S. military fatalities in Afghanistan in 2014, making this year one of the least deadliest of the war for American forces.

U.S.-led international forces have been in a support role over the last two years as the Afghan National Security Force (ANSF) took the lead of securing their own country. The ANSF includes the army and the national police force.

Most U.S. troops stayed behind in their bases while their Afghan counterparts carried out patrolling operations.

“Afghan forces have long been shouldering most of the fighting here. This year, Afghan policemen and soldiers carried out 90% of military operations, and successfully prevented the Taliban from capturing new territory,” reports WSJ. “But they also suffered heavy casualties, and still lack capabilities in areas like intelligence-gathering and air support.”

Afghanistan recognizes that U.S.-led military support is still vital to their safety.

“Afghans have mixed feelings about the drawdown of foreign troops. With the deteriorating security situation, many believe the troops are needed to back up the Afghan effort to bring peace after more than three decades of continual war,” reports AP.

The U.S.-led military presence in Afghanistan peaked at about 140,000 troops in 2010, including 100,000 Americans.

An estimated 13,000-strong NATO force, including nearly 10,800 U.S. troops, are expected to remain in Afghanistan post-2014.

The new train and support mission is expected to officially begin Jan. 1.