The bomb exploded at about 9.45 a.m. local time outside a police station in the Semdinli district of Hakkari Province -- about 77 kilometers (48 miles) from the Iraqi border, the state-run Anadolu news agency reported.
Turkish Prime Minister Binali Yildirim said eight civilians died and 10 soldiers were killed in the attack, in which a pickup truck laden with about five tons of explosives made a "suicide rush" at a checkpoint outside the station.
Sixteen soldiers and an unknown number of civilians also were injured.
The United States condemned the attack "in the strongest terms" in a statement from US National Security Council spokesman Ned Price.
No one has claimed responsibility for the attack. However, the Turkish army said the Kurdistan Workers Party (PKK)
, which has been accused of a string of bombings
targeting Turkish police and army assets, was behind the attacks.
In the NSC statement, US officials also condemned Thursday's motorcycle bombing near a police station in Istanbul, which left 10 people injured, according to Anadolu. The Kurdistan Freedom Falcons, the PKK's urban terrorist unit claimed responsibility for the earlier attack, Price said in the statement.
"This attack is just the latest in a deeply concerning trend of increasing violence by the PKK, which has killed both security personnel and civilians throughout Turkey," Price said.
"We remain steadfast in our support for our NATO ally, Turkey, and reaffirm our commitment to continue working together to defeat all forms of terrorism," according to the statement.
The Turkish army has launched an operation to find those behind the attack.
Clashes between the PKK and Turkish forces have been ongoing since a peace process crumbled in 2015, bringing an end to a two-year ceasefire.
Since then, Anadolu reports, hundreds of Turkish security forces and about 5,000 PKK members have been killed in the conflict.
The PKK is considered a terror group by Turkey, the United States and the European Union. The group first took up arms against Turkey in 1984, seeking an independent state for the country's Kurdish minority, who make up an estimated 20% of the nation's population. Tens of thousands have been killed in the conflict.
Turkey has weathered a string of terror attacks
over the past year as it faces the twin threats of ISIS and Kurdish militants, and has been under a state of emergency since a failed military coup in July.