A security guard marches past flags decorating Beijing's Tiananmen Square on Tuesday, the second day of the 17th Communist Party Congress. China's top communists met behind closed doors Tuesday at a key party congress that will reappoint the country's core leadership and promote a slate of fresh faces into powerful positions.

Beijing ? China’s ruling Communist Party offered the media a rare glimpse of two rising political stars Tuesday, giving them a chance to show themselves as self-effacing, businesslike and worthy for promotion to the senior leadership.

The public appearances by Li Keqiang and Xi Jinping on the sidelines of a major party congress were likely no coincidence, given the secretive party’s penchant for carefully stage-managed public events. It came as senior party members held closed-door discussions on appointments to the Politburo Standing Committee, the inner sanctum of power.

Li, the 52-year-old party head of the industrial province of Liaoning, and Xi, the 54-year-old party chief in the commercial heart of Shanghai, met separately with rank-and-file congress members, with foreign and state-run Chinese media on hand.

“My main mission at present is to work, but also to learn while working,” said Li, animatedly gesturing in a dark gray suit as he answered questions from reporters while meeting with other delegates from Liaoning in Beijing’s Great Hall of the People.

On the other side of the cavernous building with Shanghai delegates, Xi, looking like the CEO of a major corporation, said the city had yet to live up to Beijing’s expectations. “We have yet to achieve everything the center has required of us.”

The brief encounters were telling, if not revealing. The party congress, held once every five years, sets broad policy goals and apportions senior leadership posts. At the top of this congress’s agenda is the promotion of several officials in their 50s to replace 64-year-old President Hu Jintao and other leaders when they step down five years from now.

Li and Xi are said to be leading contenders. Li, an associate of Hu’s since the two worked together in the Communist Youth League 25 years ago, is said to be Hu’s favorite but is facing resistance from other powerful party leaders. Xi, the son of a revolutionary veteran, is a compromise candidate, liked for his competence and a heritage of political reliability.

Their political fates likely will not be known until Sunday or Monday, when the congress closes and Hu escorts the new leadership for a brief appearance before the media.

Both Li and Xi were careful to make reference to Hu or his policies while avoiding discussion of personal questions.