U.S. President Donald Trump's speech at South Korea's parliament on Wednesday received a warm welcome by the country's two main political parties and its media.

The ruling Democratic Party of Korea, in a statement, said the speech at the National Assembly "has clearly manifested strengthened alliance" between the two countries.

"President Trump allocated most of the time to addressing North Korean issues and clearly stated a strong resolve to (achieve) denuclearization and peace on the Korean Peninsula," the liberal party said, while urging North Korea to immediately halt provocative acts and return to the table to engage in dialogue.

Its conservative rival, the opposition Liberty Korea Party, called the speech "an important event which has a symbolic significance as the first one by a U.S. president in 24 years and also in reconfirming the two countries' solid alliance."

It said Trump sent a clear warning to North Korea, which should take heed of it and change its behavior.

In Wednesday's speech, Trump said, "The world cannot tolerate the menace of a rogue regime that threatens it with nuclear devastation."

"We will not permit America or our allies to be blackmailed or attacked," he said. "All responsible nations must join forces to isolate the brutal regime of North Korea to deny it any form of support, supply or acceptance."

Trump's speech was also hailed by local newspapers, with the Korea Times saying, "It is worth naming the Trump Doctrine -- peace from a position of strength -- marking an end to the absence of a distinct foreign policy for the past eight years under President Barack Obama."

"Call it the media's collective failure to see through his true colors or Trump's Cinderella moment, but Trump turned out a white knight during his speech at the National Assembly Wednesday, not just articulating what Americanism is all about but also how he wants to transform the world as the leader of the world's strongest nation," it said in an editorial.

Another English-language daily, The Korea Herald, said in an editorial that North Korean leader Kim Jong Un "must heed (Trump's) warning not to underestimate the U.S." and "must keep in mind that his reckless use of nukes will immediately lead to the end of his regime."

It stressed, however, that "the most effective realistic response to North Korean threats is the strongest pressure and sanctions rather than military might which may cause calamity on the Korean Peninsula."

The Korea Joongang Daily noted that Trump used "unusually eloquent and restrained language" in directly addressing Kim, offering the young dictator "a path to a much better future" in return for the ending nuclear and missile brinkmanship.

In a press briefing on the outcome of Trump's visit, presidential spokesman Park Soo Hyun said President Moon Jae In and Trump were able to strengthen their personal ties, while Seoul got reassurances of Washington's firm security commitment to the defense of South Korea.

Park also said the two leaders reaffirmed their intention to take bilateral relations "beyond the comprehensive alliance and toward a "great alliance."

He said they reconfirmed their principle to resolve the North's nuclear issue by peaceful means, while responding to provocative actions by overwhelming power and applying maximum pressure on Pyongyang.

After the summit on Tuesday, Moon said the two countries will "cooperate on an unprecedented level" in boosting South Korea's defense capabilities and begin talks on its acquisition and development of high-tech military hardware -- namely nuclear-powered submarines and surveillance assets, a high-level South Korean official later told reporters.

He also revealed that the two sides have finalized an agreement to lift restrictions on South Korea's ballistic missile payload.

Meanwhile, a South Korean analyst on North Korean affairs raised concerns over Trump harsh remarks on North Korea, including on the dismal human rights situation there, suggesting they may provoke a backlash from Pyongyang.

"Considering North Korea's behavioral patterns in the past, North Korea is highly likely to take Trump's speech as a declaration of war against it and the North may issue the North Korean-style declaration of holy war," Cheong Seong Chang, director of the Unification Strategy Program at the Sejong Institute.

Cheong said there is a strong possibility North Korea may carry out provocative actions such as mid-range or long-range ballistic missile launches or submarine-launched ballistic missiles.