A new crisis over Taiwan would badly affect global container ship fleets with major implications for the global economy, US Secretary of State Antony Blinken said.

The official said that China’s renewed push for reunification with Taiwan had altered the status quo of the island with profound implications for trade.

“This should be a concern for not just the United States but for countries, not only in the region, but around the world,” Blinken said.

“Why? Because if there’s any crisis regarding Taiwan, we’ve got 50% of container ships on a daily basis travelling through the Taiwan Straits. The implications of a crisis if that were disrupted for the world economy, supply chains are significant – more than significant.”

Tensions between China and Taiwan have flared intermittently since the Chinese nationalist government fled to Taiwan after being overrun by communist forces in 1949.

China continues to regard the island as a renegade province but has for the most part adopted a pragmatic approach and left it alone, despite its stated intention to eventually bring it back under Beijing’s rule.

Blinken said that approach had “fundamentally changed” as China under Xi Jinping has hardened its rhetoric towards Taipei.

He said that had implications for trade including for bulk of the world’s most sophisticated microchips that are manufactured on the island, according to comments released by the State Department.

“So everyone has a very big interest, I think, in making very clear to all involved, starting with Beijing, that the world does not want to see any kind of crisis regarding Taiwan,” said Blinken.

“The world believes that these differences need to be resolved peacefully and with peace and stability certainly in the Taiwan Strait.”

Tensions spiked in August when China carried out military exercises in six no-sail zones in apparent response to a visit by US House of Representatives speaker Nancy Pelosi that angered Beijing. VesselsValue data showed that more than 300 ships were in Taiwanese waters or were due to arrive during the four-day exercise.

Taiwan’s transport ministry advised vessels to stay well clear of the live-fire areas and Several tankers reportedly rerouted to avoid the area.