By Greg Argos

BEDMINSTER, N.J. (CBS/CNN) — President Donald Trump issued a stern warning to North Korea after reports indicated the regime has now developed the capability to build a nuclear warhead small enough to fit in a missile.

The revelations come just days after the United Nations slapped economic sanctions on the country to curb its nuclear ambitions.

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Trump said, if provoked, the United States will be ready.

“North Korea best not make any more threats to the United States. They will be met with fire and fury like the world has never seen,” Trump said Tuesday afternoon.

U.S. intelligence officials estimate North Korea has enough nuclear material to build dozens of nuclear weapons.

“We have to enforce these for these to be legitimate. We have to hold these countries accountable,” said U.S. Ambassador to the U.N. Nikki Haley.

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Secretary of State Rex Tillerson, who is in Asia this week, is urging other nations to help enforce United Nations economic sanctions against the rogue nation.

“The North Korean regime is gonna have to make a choice. They’re not gonna be able to continue their programs and keep their elites happy and keep the military happy. They’re gonna have to start making choices that they haven’t had to choose before,” said Anthony Ruggiero, a North Korea sanctions expert.

For now, it’s not getting any calmer. North Korea’s military is “examining the operational plan” to strike areas around Guam with medium-to-long-range strategic ballistic missiles, the state run KCNA said Wednesday. The statement, from a spokesman from the Strategic Force of the Korean People’s Army, warned that recent US military maneuvers — a reference to the flight of two US B1B bombers over the Korean peninsula Monday — “may provoke a dangerous conflict.”

Meantime, a new CBS News poll suggests many Americans are not confident in Trump’s ability to handle the situation with Kim Jong-un’s nuclear program, as 61 percent of people polled said they were uneasy.

That’s compared to 35 percent of Americans who said they were confident in the president’s ability.

Trump tweeted earlier Tuesday that the world needs to be “tough and decisive” against North Korea.

“After many years of failure, countries are coming together to finally address the dangers posed by North Korea. We must be tough & decisive!” Trump tweeted.

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