US Defense Secretary James Mattis made an unannounced visit to Kabul, Afghanistan, Wednesday with NATO Secretary General Jens Stoltenberg.

The visit marks Mattis' first trip to the country since US President Donald Trump announced a new Afghan strategy in late August.

At the time, Trump said he was shifting the policy to take the emphasis off troop numbers, and would rely on greater regional cooperation to stabilize the security situation in Afghanistan.

In the coming hours, Mattis is expected to meet with the Commander of US Forces in Afghanistan Gen. John Nicholson and spend time with US troops.

He's also set to hold talks with Afghan President Ashraf Ghani and other Afghan government ministers. Later, he'll hold a press conference with Ghani and the NATO chief.

US Secretary of Defense James Mattis touches down in Kabul, Afghanistan for a visit, Wednesday, 27 September.

Last week, Ghani used a substantial part of his speech at the United Nations General Assembly to praise Trump's recently announced strategy for Afghanistan and South Asia.

"With President Trump's recent announcement of his strategy to counter terror and stabilize South Asia, Afghanistan's enduring partnership with the United States and the international community has been renewed and redirected," Ghani told the audience at the UN headquarters in New York.

Hours after Mattis landed, the Afghan Interior Ministry confirmed that a rocket hit close to Kabul international airport, fired from an unknown location. It landed in an open area, and no casualties nor damage was reported, the ministry said.