A hot mic at a World War II anniversary parade caught Russian President Vladimir Putin and Chinese President Xi Jinping discussing organ transplants and the possibility of extending human life. Putin’s translator was overheard speaking about biotechnology enabling continuous organ replacement and even immortality, while Xi noted predictions that people could live up to 150 years this century, according to Reuters.

The exchange came as the leaders walked alongside North Korea’s Kim Jong Un. Neither Moscow nor Beijing has commented. The parade coincided with a summit where Putin and Xi signed over 20 agreements spanning energy, artificial intelligence, and a new gas pipeline. Xi used the occasion to warn that the world faces a choice between “peace or war.”