Vietnam's ruling Communist Party gathered for its first national congress since 2016 on Monday with a mission to select new leaders and shape policy for the next five years and beyond.

The event, the 13th congress since the Communist Party of Vietnam was established in 1930, brought nearly 1,600 delegates from across the country to Hanoi. On a foggy morning in the capital, they paid a ceremonial visit to the mausoleum of founding revolutionary Ho Chi Minh before meetings began.

Vietnamese officials traditionally visit the mausoleum ahead of important meetings and national events.

Amid stringent coronavirus testing to preserve Vietnam's comparative success in keeping the pandemic at bay, delegates will pick a new leadership team in nine days of meetings, mostly behind closed doors, aiming to bolster...