Hong Kong's judges have upheld fundamental legal principles in hearing all cases, including national security trials, Chief Justice Andrew Cheung said on Monday.

In a speech marking the start of the Legal Year, the SAR's top judge said the city's national security laws have brought with them "cases that attract heightened attention", particularly due to their political sensitivity.

But Cheung stressed the same legal principles apply in national security cases as in others.

"The presumption of innocence, the requirement that guilt be proved beyond reasonable doubt, and the right to a fair trial are all essential safeguards that remain firmly in place," he said.

"Our courts do not merely pay lip service to these fundamental principles. Judges at all levels are expected to, and indeed do, adhere to them in the adjudication of cases."

Cheung said tensions often exist between protecting basic rights and safeguarding national security, both of which the judiciary is firmly committed to upholding.

"Striking the right balance can be challenging, and outcomes in individual cases may be contentious at times, nor is the interpretation or application of newly enacted statutory provisions always straightforward," he said.

"However, it is one thing to disagree with a legal provision or a court decision in applying it, but entirely another to suggest that the justice system has been undermined by political expectations or societal atmosphere."

The chief justice also said while the departure of foreign judges from the city's top court "caused concerns in some quarters", it has not affected judicial independence.

"It is unfortunate that a few of these judges have felt unable to continue their service. They are, of course, entitled to their views, and their decisions ought to be respected. However, their premature departures do not mean a weakening of the quality or independence of the judiciary," Cheung said.

"It is true that, given the current geopolitical headwinds, recruiting overseas judges with the right stature and experience may be less straightforward than it once was. After all, overseas judges are appointed to our highest court on account of their acknowledged eminence and legal expertise, not merely to sustain the system of overseas judges for its own sake."

In 2024, five foreign judges decided to step down from the Court of Final Appeal. Following their exits, there are 10 non-permanent judges left sitting on the top court, six of them from overseas.

The presence or absence of individual judges will not undermine the integrity of Hong Kong's judicial system, the top judge added.

Cheung said the city has faced significant political, social and economic challenges in recent years, which tested the resilience of the territory's legal system and the strengths of its institutions. Despite that, he said, the judiciary continued to uphold the rule of law and ensured that legal procedures remain transparent, fair and independent.