LONDON - Leaders of Nato, the US-led military alliance in Europe, have concluded their summit in the Spanish capital of Madrid by announcing the most significant increase in troop levels on the continent in decades to confront a Russia that the alliance now labels as the "most significant and direct threat" to its members' security.

Nato levelled some unusually forthright criticism at China, pledging that it "will boost our shared awareness, enhance our resilience and preparedness, and protect against the PRC's coercive tactics and efforts to divide the alliance", using the abbreviation for the People's Republic of China.