Four U.S. troops were wounded Monday by a suicide car bomb attack near the provincial capital of Kandahar in southwestern Afghanistan, according to NATO.

A statement from the NATO Resolute Support mission said, "A vehicle-borne improvised explosive device [or VBIED] detonated in Kandahar province at approximately 2 p.m." local time. "There were a total of four U.S. service members injured, and all are in stable condition in U.S. medical treatment facilities."

Qudratullah Khushbakht, a spokesman for the provincial governor's office, said the attack occurred near Kandahar Air Field, where U.S. and coalition troops are based, Stars & Stripes reported.

The Taliban immediately claimed responsibility for the attack. In a statement, the militant group's spokesman, Qari Yousuf Ahmadi, said "heavy losses" had been inflicted in the suicide car bombing.

Next to neighboring Helmand province to the west, Kandahar, birthplace of the Taliban, is the second-deadliest Afghan province for coalition troops. More than 560 coalition troops have been killed there since 9/11, according to the website icasualties.org.

The U.S. troops in Afghanistan have the dual mission of training, advising and assisting the Afghan National Defense and Security Forces (ANDSF) and also conducting counter-terrorism operations against the Taliban, al-Qaida, and the Islamic State of Iraq and Syria offshoot known as Islamic State-Khorasan Province.

Since last February, U.S. Army Gen. John Nicholson, has been lobbying for additional troops and air power to reverse Taliban gains.

In August, President Donald Trump authorized the deployment of an additional 3,500 troops, while saying his initial instinct was to withdraw American troops and end the 16-year U.S. involvement in Afghanistan.

Last week at NATO headquarters in Brussels, Nicholson said that U.S. troops through most of 2017 fought at their lowest levels of capability since the war began in late 2001.

"It was the lowest level of capability and the highest level of risk we've faced in this time," he said at a news briefing. The official number of U.S. troops in Afghanistan, or Force Management Level, is about 8,500 although Defense Secretary Jim Mattis has said that about 11,000 are actually on the ground.

Under a four-year plan approved by Afghan President Ashraf Ghani, the military strategy is to go on the offensive against the Taliban with expectations that the added pressure will bring the group to the bargaining table, Nicholson said.

"This, coupled with pressure on the external enablers of the insurgency -- as well as social pressure at the ballot box, with the elections over the next two years -- is all designed to bring the Taliban to the table," he said. "So this is a fight-and-talk approach."

-- Richard Sisk can be reached at Richard.Sisk@Military.com.