Afghan security forces have identified key areas of the country that must be secure for elections later this year.
The Afghan capital is now the main focus of the anti-Taliban fight, with U.S. special forces conducting raids.
Afghanistan's President Ashraf Ghani has put a peace offer on the table, and analysts say the ball is in the Taliban's court.
U.S. Defense Secretary Jim Mattis said Tuesday he believes victory in Afghanistan is still possible.
Last month, 800 more U.S. soldiers arrived in Afghanistan, bringing the total to nearly 15,000 troops.
The Khorasan Province, an ISIS affiliate in Afghanistan, claimed responsibility for the Kabul bombing.
Two missiles fired from a U.S. drone hit a militant facility in neighboring Afghanistan, killing 21 insurgents.
U.S. officials have conveyed messages to Taliban representatives in Qatar, urging talks with the Afghan government.
Ghani spoke at the 2nd Kabul Process Conference attended by representatives from more than 20 countries and organizations.
The Taliban has called for direct talks with the US in an apparent policy reversal after months of escalating attacks.