Once seen as relatively secure, the sprawling Afghan capital of Kabul is becoming the main focus of an intensified US-backed battle against the Taliban this year after a series of high-profile attacks exposed major gaps in security.
"Kabul is our main effort. To harden Kabul, to protect the people of Kabul and the international community that are here," US General John Nicholson, the top US commander in Afghanistan, told a group of reporters on Wednesday.
The remarks underscored the high degree of concern about the Taliban's intent to stage high-profile attacks in Kabul, which are aimed at undermining the Afghan government and international resolve after 16 years of war.
They are also a reminder that while US and Afghan officials speak with growing confidence about the prospects of peace talks with elements of the Taliban, the military is also making long-term preparations for an extended conflict, including in the capital.
Nicholson said Kabul's exponential growth from about 500,000 people in 2001 to five million today created a haphazard sprawl that was hard to secure. US intelligence agencies were helping Afghanistan map the city so police and soldiers can better design barriers and checkpoints.
In the past year, insurgents have staged massive bombings in the Afghan capital, including one in January that killed more than 100 people and another in May 2017 near the German embassy.
No group claimed the May 2017 attack but Afghan and US officials blamed the Haqqani network, a violent militant group affiliated to the Taliban.
The Taliban claimed the second attack but many officials say it bore the hallmarks of the Haqqanis, who the United States says enjoy safe haven in neighboring Pakistan.
US President Donald Trump approved a more aggressive strategy last year that included more US combat advisers and air strikes, and fighting is expected to pick up in the coming weeks.
A group of newly arriving US Army advisers would partner with some of the Afghan troops securing Kabul. Commandos would carry out intelligence-driven raids throughout the city, something Nicholson said was already ongoing.
The goal would be to eliminate Taliban strongholds as well as Taliban facilitators, which included criminal enterprises that, for a price, gave the insurgents shelter or weapons.
Nicholson's comments came during a trip to Afghanistan by US Defense Secretary Jim Mattis, whose delegation navigated some of Kabul's checkpoints and blast walls while moving between US military and Afghan government compounds on Tuesday, helicopters buzzing overhead.