North Korea is more dangerous now because of the progress it has made on its nuclear capabilities in recent years, former national security advisor John Bolton told CNBC on Wednesday.At a military parade on Saturday, North Korea showed off its new weapons including a huge intercontinental ballistic missile (ICBM) that could potentially be more lethal — either due to multiple warheads or a bigger payload, Reuters reported, citing military analysts.”The fact is that we wasted a lot of time with Trump’s failed diplomacy with North Korea,” Bolton told CNBC’s “Squawk Box Asia.””Rogue states need time to perfect their nuclear capabilities, their ballistic missile capabilities. That’s what Kim Jong Un was doing,” he said referring to the North Korean leader.Since becoming president, Trump has held two nuclear summits with Kim in Singapore and Vietnam — but neither yielded much result. Trump tried to push Pyongyang to give up its nuclear weapons and dangled the prospect of an economic boost to the country, which has struggled under the weight of crippling international sanctions from the United Nations as well as the U.S.The sanctions are aimed at cutting off funding for North Korea’s nuclear arms and ballistic missiles programs. Experts previously said that Kim wants to see the sanctions eased without losing the strategic benefits of his weapons of mass destruction.”So, I do think it’s more dangerous now because of the progress that North Korea has made,” Bolton said.He added that in the event that Democratic presidential nominee Joe Biden wins the November election, handling North Korea will “be a tough play for the Biden administration.”Public opinion hardening against ChinaBolton also weighed in on rising tensions between China and Taiwan, and the U.S. perception of Beijing.”China is a much bigger question, a more existential question for the United States,” Bolton said.Taipei has been building closer ties with Washington, and drawing much protests from Beijing. China considers Taiwan as part of its territory that must one day be reunited with the mainland and should therefore have no right to engage in international diplomacy. While the U.S. has no formal diplomatic ties with Taiwan, it is the island’s most powerful international backer and its largest arms supplier.”I think on Taiwan, what China really wants is for Taiwan to fall into its lap like a ripe fruit,” Bolton said. “They don’t want war, they don’t want the island devastated. But on the other hand, they definitely want it back. The Taiwanese do not want to go back.”I would not count on simply reverting back to what it was like when Obama left office.John Boltonformer U.S. national security advisorIf Biden wins the election, it will be a tough call for his administration, according to Bolton. Under the Trump administration, the relationship between the U.S. and China deteriorated significantly — first due to a trade war, then a battle for technological dominance. On top of that, Trump has repeatedly blamed China for the coronavirus pandemic, which has killed at least 215,000 people in the U.S. so far.”Public opinion in the United States is hardening against China,” Bolton said, adding that Beijing’s handling of the coronavirus created a negative perception of the world’s second-largest economy in the U.S. as well as in other countries.While former president Barack Obama’s administration was “very accommodating” to China, there are no guarantees that Biden, if he wins the election, would follow suit due to the change in public opinion, Bolton said.”I would not count on simply reverting back to what it was like when Obama left office,” he added.