Taiwan’s Defense Ministry said that it had detected 44 Chinese military aircraft around the self-ruled island Monday, with 37 crossing what is known as the median line dividing the Taiwan Strait and flying south of the island — just ahead of the U.S. presidential election.

It was the third day in a row that a large number of Chinese military aircraft had been reported in the area, with the Defense Ministry in Taipei saying the earlier instances had been part of exercises that saw them head into the Western Pacific for long-distance flights.

Taiwan's Defense Ministry said it had responded by deploying aircraft, warships and shore-based missile systems.

China — which views democratic Taiwan as its “core of core issues” and regards the island as a renegade province that must be unified with the mainland, by force if necessary — regularly sends military aircraft around the island. Last month, it wrapped up a day of large-scale military exercises around Taiwan with a hint that more shows of force were to come.

Taiwan has become a contentious issue in the U.S.-China relationship, as Washington, bound by law to provide Taipei with the means to defend itself, continues to anger Beijing by selling weapons to the island. Last month, the U.S. agreed to sell a $2 billion missile system to Taiwan.

Observers say China sometimes uses the military exercises to simultaneously build up its capabilities and express its displeasure at the U.S. moves.

Monday’s flights, however, come a day before the U.S. heads to polls to select a new president, with Democratic Vice President Kamala Harris facing off against Republican former President Donald Trump.

China will be closely watching the election, but Beijing is unlikely to put much hope in either candidate easing tensions in the contentious U.S.-China rivalry — especially when it comes to Taiwan.

Trump last month pledged to impose additional, massive tariffs on China if it were to "go into Taiwan," but also lamented the amount of U.S. money spent on the island, hinting that it should have to pay for American protection.

Harris’ stance toward Taiwan had remained unclear until last month, when the vice president stressed that her administration would maintain Washington's “one China" policy while “supporting Taiwan's ability to defend itself.”