A senior US Defense Department official says a Chinese blockade of Taiwan's surrounding seas and airspace would likely fail.

Ely Ratner, US Assistant Secretary of Defense for Indo-Pacific Security Affairs, testified before the House Armed Services Committee on Tuesday. He commented on China's increasing military pressure on Taiwan.

Ratner said defense officials believe, based on their analysis, that Taiwan would have options with the international community to ensure the delivery of industrial resources, raw materials, energy and other critical items in the event of a Chinese military blockade.

Ratner said a blockade "would be a huge risk of escalation" for China in which it would l likely have to consider whether or not it was willing to ultimately start attacking commercial maritime vessels.

He said it would be a "huge miscalculation" for Beijing.

Ratner also said that Washington should maintain its decades-long policy of strategic ambiguity toward Taiwan.

He said the effects of changing US policy to strategic clarity "would increase political tensions and make conflict more likely."