The insurgent group’s opponents will “take every counteraction it deems appropriate against the occupying forces,” a Taliban spokesman tweeted Saturday.
Security checkpoints were hardened in Kabul and other cities, and military patrols were ramped up on their streets, according to reports.
The notice came on May 1, the date that Trump and Taliban leaders had agreed on as the end of the two-decade American military presence in the strife-torn country.
Taliban forces halted assaults on alliance forces after signing a peace agreement that designated the withdrawal date last February.
But President Biden prolonged the deadline, promising instead to withdraw US troops out by Sept. 11.
Taliban insurgents in Afghanistan attacked and overran a key army base in southeastern Ghazni province Saturday, capturing dozens of soldiers and killing several others.
The latest attack came on a day when the United States and NATO partners formally began withdrawing their militaries from the country after almost 20 years of war.
Two senior provincial council members told VOA the Afghan army had posted dozens of its forces at the base outside the provincial capital, also named Ghazni, before the pre-dawn radical attack.
Local media reports said the continuing disputes had lasted several hours and killed at least 17 soldiers.
The Afghan army chief, Gen. Mohammad Yasin Zia, who is also the current defense minister, verified to reporters in Kabul the fall of the security apparatus to insurgents, but he gave no further details.
Taliban spokesman Zabihullah Mujahid said its fighters had also taken heavy and light weapons besides catching 25 army staff and killing “a number of others.”
Afghan officials Saturday raised the death toll to at least 30 from an overnight truck bombing in Pul-e-Alam, the capital of eastern Logar province. The strong blast late Friday injured more than 100 others. Almost all the victims were said to be Afghan civilians. The Taliban did not comment on the attack but Afghan officials blamed the insurgents for planning the massacre.
Critics fear the violence in Afghanistan will escalate unless the Taliban and the Afghan government continue their delayed peace talks and strike a power-sharing deal before all foreign troops exit the country in the next few months.
The troops were to have gone Afghanistan by May 1 in line with an agreement Washington signed with the Taliban in February 2020 in trade for a pause of insurgent attacks on foreign forces and counterterrorism assurances.
Nevertheless, U.S. President Joe Biden announced last month that the drawdown would begin May 1 and stop by September 11, the 20th anniversary of al-Qaeda-plotted attacks on America. Biden cited logistical reasons for missing the deadline.