By Shawn Snow and Mackenzie Wolf, Military Times–

U.S. Defense Secretary Jim Mattis arrived in Afghanistan on Monday for meetings with top Afghan and American officials.

The visit, which the Pentagon did not previously make public, comes as President Donald Trump’s administration evaluates its next moves in the 15-year campaign. Army Gen. John Nicholson, the war’s top commander, has requested an unspecified number of additional troops — believed to number in the thousands — who can accelerate military training for the Afghan security forces and, it is hoped, reverse the Taliban’s surging momentum in several parts of the country.

It’s Mattis’ first trip to Afghanistan as defense secretary. Trump’s national security adviser, Army Lt. Gen. H.R. McMaster, was there for similar meetings last week.

Mattis has been traveling throughout the region since last week, visiting key leaders in Saudi Arabia, Egypt, Israel, Djibouti and Qatar.

In Afghanistan, where roughly 8,400 American troops continue to advise and assist local forces, the U.S has stepped up operations to target Taliban commanders. On Saturday, officials announced an airstrike on April 17 killed Quari Tayib, who had launched attacks against U.S. forces.

Meanwhile, the U.S. is conducting counter-terror operations against Islamic State loyalists — the group is known as ISIS-Khorasan, or ISIS-K — near the Afghan-Pakistan border. A U.S. Green Beret,  Staff Sgt. Mark De Alencar, was killed in action there in early April.

U.S. forces recently targeted the group with a massive airstrike, bombing a cave complex occupied by ISIS fighters.

The use of such a large munition — nicknamed “the mother of all bombs,” or MOAB — elicited  criticism and raised questions about the Islamic State’s capabilities in the war-torn country.

While U.S. counter-terror efforts have focused on al-Qaida and ISIS fighters in Afghanistan, a resurgent Taliban has managed to overrun large swaths of territory, threatening U.S. efforts in the region.

The U.S. is pushing for political reconciliation between the the Taliban and Afghanistan’s government in Kabul. Several secret meetings took place in Qatar this fall. But those negotiations have produced few results, and Taliban militants continue to threaten numerous population centers.

Speaking at the Hudson Institute think tank last week, Pakistan’s former ambassador to the U.S., Husain Haqqani, said the international community has been pushing for reconciliation since 1993. “Are we just chasing a pipe dream,” he asked panelists at the event.

The problem with reconciliation is that the Taliban have little incentive to negotiate, according to former U.S. Ambassador to Afghanistan Zalmay Khalilzad. Many of their fighters find sanctuary in Pakistan, and they’re receiving support from Russia and Iran.

Khalilzad sees only two ways in which the dynamics between the Afghan government and Taliban change: that Pakistan changes and sees a strategic benefit to denying them sanctuary, or a decisive battle shifts in favor of one side in the conflict.