China expands nuclear program with activity at seven sites

The record

Written from the 1 report below. Nothing here is unsourced.

China is conducting construction and upgrades at multiple strategic nuclear facilities including sites in Pingtong, Zitong, and Lop Nur.
Analysts from the Federation of American Scientists estimate the Chinese nuclear arsenal has grown to 620 warheads.
The expansion appears intended to support new delivery systems.
Officials in China maintain that their nuclear strategy remains defensive and adheres to a no-first-use policy.

1 report

English national1

All filed from India

Named China · Lop Nur · Pingtong · Zitong · Federation of American Scientists

The 1 report is listed beside the record.

Answers cite the reports above, or say they can't.