Washington, Nov 20 (IANS): The Smithsonian Institution, a world-renowned US museum and research complex, announced that it will temporarily close all its museums and the National Zoo located in Washington, D.C. from November 23 due to the resurgence of new Covid-19 cases.

"The Institution's top priority is to protect the health and safety of its visitors and staff. We will use this time to reassess, monitor and explore additional risk-mitigation measures," Xinhua news agency quoted the Smithsonian as saying in a statement on Thursday.

"Due to the changing nature of the situation, we are not announcing a reopening date at this time," it said.

The institution previously closed its museums and the National Zoo in March, and had a limited reopening to the public in September.

The Smithsonian Institution has 19 museums, nine research centres, and many affiliates around the world.

As of Friday, the US is the worst-hit country with the world's highest number of Covid-19 cases and deaths at 11,710,084 and 252,484, according to the Johns Hopkins University.

Due to the grim situation, the US Centers for Disease Control has advised Americans not to travel for Thanksgiving next week.