The Chinese Communist Party has concluded a key plenary session after issuing a communique with a slogan that expresses loyalty toward President Xi Jinping.

The 19th Central Committee of the Communist Party concluded the session in Beijing on Wednesday, ahead of the opening of the party's National Congress on Sunday.

Deliberating draft amendments to the Communist Party Constitution was high on the agenda. The amendments are aimed at further consolidating Xi's authority as he seeks an unprecedented third term as president.

The communique emphasizes the Communist Party has established Xi's core position in the Central Committee and defined the guiding role of Xi's thoughts on socialism for a new era.

It says this is "of decisive significance for advancing the cause of the party and the country in the new era and for driving forward the historic process of great national rejuvenation."

Wednesday's meeting also reflected on the past five years, with the communique saying the Central Committee has accomplished much, scoring major achievements that have captured the attention of the world.

Speculation is on the rise that Xi, now aged 69, will likely be granted a rare third term in the upcoming five-yearly National Congress, despite standing tradition that calls for party leaders to retire at 68.