U.S. Defense Secretary Chuck Hagel has arrived in Afghanistan and says he believes Afghans will prevail against a surge in Taliban violence in the capital.

Hagel's unannounced visit on Saturday to Kabul is likely his last as Pentagon chief. He submitted his resignation Nov. 24 and President Barack Obama announced Friday that he will nominate Ashton Carter to succeed Hagel.

In remarks to reporters flying with him from Washington, Hagel was strikingly upbeat about prospects for long-term stability in the country whose previous Taliban rulers sheltered al-Qaida and its leader, Osama bin Laden.

Hagel will meet with President Ashraf Ghani and Chief Executive Abdullah Abdullah, and with top US military commanders.