Prime Minister Lee Nak-yon reacted negatively Wednesday to calls for South Korea to possess nuclear weapons, saying the move would undermine Seoul's calls for North Korea to denuclearize, trigger a nuclear arms race and put the country under international sanctions.

Calls for nuclear armament have gained traction as Pyongyang stepped up its nuclear and missile programs, with two nuclear tests last year, as well as a series of missile launches, including those capable of reaching the continental US.

Reflecting such calls, the main opposition Liberty Korea Party adopted a demand Wednesday for the redeployment of US tactical nuclear arms as its official party line during a general meeting of its lawmakers.

"If we say we're going to have nuclear weapons while putting forward the goal of North Korea's denuclearization, it will end up undermining the justification of our demand for denuclearization and further accelerating nuclear armament in Northeast Asia," Lee said in an interview with YTN television.

"It will also mean that we have to be prepared for international economic sanctions. This is not an issue that we can make a hasty decision on," he said.

But Lee then said the country should consider introducing nuclear-powered submarines to cope with growing threats from the North.

"Nuclear submarines are another issue," he said. "It's time for us to think about introducing nuclear submarines."

Lee also said that South Korea and the US are on the same page on the North Korea problem, rejecting concerns about so-called "Korea passing" -- the belief that South Korea might be sidelined by the US and other key players in efforts to resolve the crisis.

Lee said the situation is very serious.

"It's true that the situation is very grave. This is a situation that was unimaginable in the past," he said. "It won't be easy for Chairman Kim Jong-un to go ahead and play with fire if he's eager to keep the existence of the system he leads. The US can prepare military options, but it won't be an easy decision to put them into action."

Tensions on the Korean Peninsula soared higher after the North threatened last week to fire four Hwasong-12 intermediate-range ballistic missiles into waters just 30-40 kilometers off the US-controlled Pacific island of Guam.

In response, US President Donald Trump has openly talked about military options.

On the issue of pesticide-contaminated eggs, Lee expressed confidence that the government will bring the situation under control quickly, saying how it handles the case will determine whether or not the current administration is competent.

"Just as we resolved the avian influenza issue quickly, I'm sure the situation will go back to normal within a few days too," he said.

Lee also said that the situation isn't as bad as had been feared because the eggs can be tracked to where they were produced. He also said that the government's inspection of eggs will be completed Thursday night and unaffected eggs will be put back on the market Friday morning. (Yonhap)