© Kamaile Casillas / Reuters
A US Air Force B-1B Lancer and Republic of Korea air force F-15s
Washington and Seoul have "discussed the option" of putting nuclear weapons on the Korean Peninsula, according to US Secretary of Defense James Mattis, who said there are "many military options" available amid the North Korean crisis.

During a Monday press conference, a reporter reminded Mattis that South Korean Defense Minister Song Young-moo told his parliament following a visit to Washington that the two officials had discussed "the possibility of small tactical nukes."

When asked whether it was possible that such nukes might be deployed to the Korean Peninsula, Mattis said the two sides had "discussed the option," but declined to elaborate.

"We have open dialogue with our allies on any issue that they want to bring up. We're not only friends, we're trusted allies. And we bring up all issues with one another," he said.

Mattis also said there are military options the US can take with North Korea which would not put the South at serious risk, but he refused to explain such options in detail.

"There are many military options, in concert with our allies that we will take to defend our allies and our own interests," Mattis said, agreeing with a statement by US Ambassador to the UN Nikki Haley on Sunday.

When pressed on whether those military options included "kinetic"options that use lethal force, Mattis said: "Yes, I don't want to go into that."

Mattis was also asked whether he believed the newest UN sanctions against Pyongyang were working. Those sanctions include capping crude oil supplies to North Korea at present levels and reductions in other commodities, as well as banning textile imports.

"What we've done with the sanctions is we are putting the leader in North Korea in a position to be aware that the international community, voting unanimously twice now in the United Nations Security Council, seeing the increasing diplomatic isolation that comes with it, comes with the economic sanction that there's a penalty to be paid for ignoring international concerns and norms," Mattis said, referring to the sanctions which were put in place following North Korea's sixth and most powerful nuclear test earlier this month.

Meanwhile, Mattis confirmed that Washington will not be shooting down North Korean missiles unless they pose a direct threat to the US.
"...Those missiles are not directly threatening any of us....the bottom line is that, when the missiles - were they to be a threat, whether it be to US territory, Guam, obviously Japan... Japan's territory - that would elicit a different response from us."
US President Donald Trump warned last month that North Korea would face "fire and fury" if it continued to threaten the country and its allies. Haley said during a Sunday interview with CNN that those words were "not an empty threat."

"...We all know that basically if North Korea keeps on with this reckless behavior, if the United States has to defend itself or defend its allies in any way, North Korea will be destroyed..." Haley said.

Mattis' comments came as the US military staged bombing drills with South Korea on Monday, flying a pair of B-1B bombers and F-35 fighter jets over the Korean Peninsula in a show of force against Pyongyang.

Meanwhile, the head of Russia's upper house Committee for International Relations said on Monday that Moscow simply cannot allow the US or any nation to provoke Pyongyang into a military conflict, as that could mean the use of weapons of mass destruction near Russia's borders.

Both Russia and China have urged all sides against unnecessary escalation of the conflict, and have proposed a 'double-freeze' plan which would see Pyongyang suspend its nuclear and ballistic missile tests in exchange for a halt in joint US-South Korea military exercises. That plan has been rejected by Washington.

North Korea showed no signs of backing down on Monday, saying that the more threats it receives from the US and its allies, the faster it will complete its nuclear force.

A North Korean Foreign Ministry spokesperson also referred to the newest UN sanctions on Monday as "the most vicious, unethical and inhumane act of hostility to physically exterminate the people of the DPRK [Democratic People's Republic of Korea], let alone its system and government," Reuters reported.