Kim Jong-un was spotted wearing new streetwear and a new pair of heels at a fashion event on the outskirts of the US capital, Washington.
Kim, who was photographed walking past a large crowd of onlookers on Tuesday, is widely expected to be present at the opening of a new retail store and fashion show next month, which could be the first big milestone in his rule.
The country’s top leader is the world’s second-richest man after US President Donald Trump.
But analysts warn that the country’s political climate is increasingly hostile to the West and is likely to be affected by the US presidential election on November 8.
Mr Trump’s victory in November has triggered a new round of protests in North Korea.
“The regime will be looking for any way to maintain their control,” said Lee Seok-hyung, a political science professor at Seoul National University.
“We will see whether the Kims (will) be able to make any changes and, if so, what that means.”
The new store is expected to open in late April and the new fashion show will be held in June.
Mr Kim also visited New York’s Bryant Park and toured the Macy’s department store in the US city.
North Korea’s leader, Kim Jong Nam, has been visiting the US since the start of the year, visiting the Pentagon and other military facilities in Florida, New Jersey and New York.
“In recent days, the US military has been on high alert,” said Jonathan Cook, a senior fellow at the Washington-based Atlantic Council think-tank.
“They are looking to be prepared for any contingency they might have if the US decides to pull back from the regime and Kim is forced to step down.”
North Korea has been heavily criticised for its human rights record, including its alleged human rights abuses.
The government has been criticised for restricting freedom of expression and information.
“Kim Jong Un is showing the world that North Korea is a repressive regime,” Mr Cook said.
“And it is proving to be a big threat for the West.”
The US has accused North Korea of conducting a nuclear test and long-range rocket launch last month.
The launch triggered an emergency meeting of the UN Security Council, which is due to meet on Tuesday.
North Korean state media has also warned the US and South Korea to “prepare for war” if the United States launches a preemptive strike against the North.
The US, which has more than 300,000 troops in South Korea and Japan, is the most powerful military in the region.
The UN Security Committee said the North should immediately halt its nuclear and missile tests and agreed on a number of measures to strengthen UN sanctions against North Korea, including a suspension of North Korean imports of food, coal, iron ore and timber.