U.S. Defense Secretary Jim Mattis has arrived in the Afghan capital to take stock of the war, with emphasis on prospects for drawing at least some Taliban fighters into reconciling with the Afghan government.

The visit, which was not announced in advance due to security concerns, comes as the U.S. injects new resources into the stalemated war. Mattis told reporters that he thinks victory is still possible — defined as a political settlement with the Taliban.

Mattis planned to meet with Gen. John Nicholson, the top American commander in Afghanistan, as well as Afghan President Ashraf Ghani.

Last week, senior U.S. intelligence officials gave Congress a decidedly mix forecast for Afghanistan. They said that while Afghan forces are getting better, the Taliban is likely to threaten Afghan stability in 2018.