A US military U2 reconnaissance aircraft lands at the Osan US military air base south of Seoul on Sunday. South Korea will soon announce its own tougher sanctions on North Korea, an official said, a move set to further heighten tensions as Seoul and Washington begin their largest-ever joint military exercise. Photo: AFP

 
The US and South Korea are scheduled to launch their largest ever joint military exercises on the Korean Peninsula on Monday, a sign of growing tensions in the region and coming hard on the heels of tough new UN Security Council-approved sanctions on North Korea. 

Analysts said the scale of the exercises indicates a shift in mentality from the US on how to resolve the nuclear issues on the Korean Peninsula and warned that pressuring North Korea too hard would not be conducive to the denuclearization process and peace of the peninsula.

According to South Korea's Yonhap News Agency, the US will send more than 15,000 troops to the joint military drills. South Korea is set to commit some 300,000 soldiers, more than double its usual deployment.

The drills will be twice the size of last year's, South Korean Defense Minister Han Min-koo said, the BBC reported.

Key Resolve will include Operation Plan 5015, a wartime plan jointly adopted by Seoul and Washington in June 2015 to prepare for pre-emptive strikes against Pyongyang if necessary and destroy its weapons of mass destruction, according to the Korea Times.

Foal Eagle - a field exercise also involving US strategic assets, including a naval fleet led by an aircraft carrier and nuclear-powered submarines - is also expected to be far bigger than before and will last until April 30.

Nuclear-powered aircraft carrier USS John C. Stennis will take part in the annual drills. This year's amphibious maneuvers - known as the Ssangyong exercises - will be larger and more elaborate than ever before, with 7,000 US troops practicing coming ashore aboard Osprey tilt-rotor aircraft and from landing craft from the USS New Orleans, The Telegraph reported.

In addition, the drills will for the first time simulate scenarios in which the North Korean regime has collapsed, according to the Telegraph.

Seoul says the drills are defensive in nature but Pyongyang has slammed them as a preparation for war.

North Korean leader Kim Jong-un ordered his military to be on standby for pre-emptive nuclear strikes last week.

"The scale of the drills shows that the US believes it is necessary to raise pressure on North Korea given the latest developments in its nuclear and missile programs. The US also wants to test its Operation Plan 5015 to see if it is truly capable of tackling the new situation on the peninsula," Zheng Jiyong, director of the Center for Korean Studies at Fudan University told the Global Times Sunday.

"The drills show that the US and South Korea have lost their patience with North Korea. It is a sign that the US believes dialogue alone will not persuade Pyongyang to give up its nuclear programs and is considering other options, including military ones," Zheng said.

He warned of dangerous consequences.

"The joint exercises between the US and South Korea will make it more difficult for North Korea to give up its nuclear programs. The current situation is very sensitive, [such moves] could create chaos on the peninsula or even the entire Northeast Asia," Zheng noted. 

Seoul announces sanctions

South Korea will announce this week its own tougher sanctions on North Korea, a Seoul government official said on condition of anonymity.

The Seoul official did not elaborate on the South's separate sanctions. Yonhap reported they would include banning any ships which have previously docked in the North Korean ports.

A group of North Korean individuals and organizations believed to be involved in weapons development will also be added to a blacklist, it said, citing a government source.

In February, in an unprecedentedly tough move, the South announced the total shutdown of a jointly run industrial park in North Korea, saying Pyongyang had been using it to fund its nuclear weapons programs.

Agencies contributed to this story