U.S. Republican presidential hopeful Nikki Haley said Tuesday that China is by far the "greatest threat" to national security as she unveiled a set of plans to deal with its rise, including the need to deepen "military ties" with Japan and other countries in Asia.

Haley, who was U.S. ambassador to the United Nations in the Donald Trump administration, said at a Washington think tank that China is a central question for the current president and for whoever will hold the office after the 2024 election, given that the United States is Beijing's "No. 1 target."

Nikki Haley. (Anadolu Agency/Getty/Kyodo)

"We're falling behind. But China is moving forward faster than ever," Haley said at the American Enterprise Institute as she seeks to elevate her single-digit support in opinion polls in vying for the Republican presidential nomination.

Haley said Trump, who maintains a lead in the increasingly crowded nomination race, "did too little" about the Chinese threat apart from trade issues, and slammed President Joe Biden for being too soft on the Asian power.

Haley, also a former South Carolina governor, said Biden's approach toward China has been "much worse" than Trump's and accused the incumbent of expanding the "list of failures" on almost every front.

She claimed the mistakes range from lackluster efforts to investigate the origins of COVID-19 and prevent China from stealing cutting-edge technologies to lagging behind in upgrading military capabilities.

"If China can do it, America can too and we can do it far better," she said. "We must also rally nations to our side. We should deepen our military ties with Japan, South Korea and Australia and forge stronger bonds with India and the Philippines."

The presidential hopeful also urged U.S. officials to shake European countries from "their slumber" regarding China and prompt them to do more to prepare for a potential contingency involving Taiwan. China, which views Taiwan as part of its territory, to be brought under its control by force if necessary, has been intensifying its military activities around the democratically ruled island.

"European countries are even further behind than we are in recognizing the Chinese threat," Haley said. "We and our allies should give Taiwan everything it needs to defend itself. We should make sure the American naval presence in the Taiwan Strait remains strong."

The 51-year-old, speaking at a time when most other candidates have yet to offer foreign policy specifics, also weighed in on Ukraine. The United States must provide more assistance to Ukraine to help it fight off the invasion, she said, as a Russian defeat would be an "enormous loss for China and a true victory for peace."

"China is watching the war in Ukraine with great interest," she said. "China is seeing what it most fears if it invades Taiwan."