President Donald Trump could send B-52 nuclear bombers to the Korean peninsula as the arms race with Kim Jong-un's North Korea continues to escalate.

The annual Foal Eagle military exercise, involving American and South Korean land, air and naval forces, kicked off yesterday.

It comes only days after Pyongyang launched four ballistic missiles 600 miles into the Sea of Japan in an alarming show of strength.

The US has a large fleet of B-52 bombers (pictured), some of which can carry nuclear weapons

A US military official told the Korea Times the B-52 and B-1B strategic bombers at Andersen Air Force Base in Guam might join a joint exercise with South Korean forces.

North Korea said this week its missile launches were training for a strike on US bases in Japan, as President Trump warned Kim of 'dire consequences' and deployed missiles to South Korea.

The regime also released pictures of Kim Jong-un watching the launch of the missiles and applauding with a wild grin on his face.

Three of the four missiles fired, pictured, came down provocatively close to US ally Japan, in waters that are part of its exclusive economic zone, representing a challenge to US President Donald Trump

Three of the four missiles fired Monday came down provocatively close to US ally Japan, in waters that are part of its exclusive economic zone, representing a challenge to US President Donald Trump.

The Foal Eagle exercise will involve 300,000 South Korean troops and 15,000 US personnel and will last until the end of April.

The aircraft carrier USS Carl Vinson is steaming across the Pacific to join the exercise.

It is carrying 24 F/A-18 Super Hornet fighter jets, 10 S-3 Viking anti-submarine aircraft, four EA-6B Prowler tactical jamming aircraft and four E-2 Hawkeye early-warning planes.

US Secretary of Defense James Mattis spoke on the phone to his opposite number in South Korea, Han Min-koo, and said Washington remained 'steadfast in its commitment' to Seoul.

North Korea news sources showed the country's leader, Kim Jong-Un, smiling and clapping as the nuclear-armed nation launched three missiles in training for a strike on US bases in Japan

Pentagon spokesman Captain Jeff Davis said: 'He further emphasized that any attack on the United States or its allies will be defeated, and any use of nuclear weapons will be met with a response that is effective and overwhelming.'

In a phone call, Trump and Japanese Prime Minister Shinzo Abe warned that the threat from North Korea had 'entered a new stage.'

Meanwhile, Washington and Seoul have agreed to deploy a US missile defense system called THAAD to South Korea, which has infuriated China, the North's key diplomatic ally and crucial to efforts to persuade it to change its ways.

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Kim Jong-Un, pictured, gave the order for the drill to start, North Korea's official Korea Central News Agency reported. 'Feasting his eyes on the trails of ballistic rockets,' he praised the Hwasong artillery unit that carried it out, the government news agency said

The news agency commented said the missiles are 'tasked to strike the bases of the US imperialist aggressor forces in Japan in contingency.' Pictured: The four missiles

'The four ballistic rockets launched simultaneously are so accurate that they look like acrobatic flying corps in formation, he said,' the agency added, referring to Kim. Photographs published by Rodong Sinmun newspaper showed Kim watching the missiles rise into the air

And the UN Security Council scheduled an emergency meeting for Wednesday after a request by Washington and Tokyo to discuss additional measures following the launch.

Under UN resolutions, Pyongyang is barred from any use of ballistic missile technology, and the US ambassador to the UN, Nikki Haley, said on Twitter that the world 'won't allow' North Korea to continue on its 'destructive path.'

THADD, or Terminal High Altitude Area Defense, systems are in place in Hawaii and Guam to defend against North Korea but this is the first time the US has deployed one in South Korea, NBC News reported.

Parts of the THAAD system arrived in South Korea by Monday, despite Beijing's proclamation that the US defense system is 'a clear, present and substantive threat to China's security interests.'

The Defense Ministry said the missiles flew about 539 nautical miles after being launched from Tongchang-ri (Sohae Satellite Launching Station). Three missiles fell within Japan's exclusive economic zone (pictured light blue), 188 miles to 215 miles west of the Oga Peninsula

The attack by North Korea comes as global condemnation of the regime swelled. Pictured: A US Air Force reconnaissance aircraft landing at Osan Air Base near Seoul, South Korea, on March 6

On Monday, the US military began deploying an anti-ballistic missile defense system, 'Terminal High-Altitude Area Defense' (THAAD), to South Korea following the attacks. The parts are arriving at Osan US Air Base in Pyeongtaek, south of Seoul

US President Donald Trump and Japanese Prime Minister Shinzo Abe warned that the threat from North Korea had 'entered a new stage.' Pictured: Abe and Trump at Trump's Mar-a-Lago resort on February 11

Trump has described North Korea as a 'big, big problem' and vowed to deal with the issue 'very strongly.'

White House spokesman Sean Spicer said Monday the administration was taking steps to 'enhance our ability to defend against North Korea's ballistic missiles.'

The New York Times reported at the weekend that under former president Barack Obama the US stepped up cyber attacks against North Korea to try to sabotage its missiles before launch or just as they lift off.

Washington and Seoul have agreed to deploy a US missile defense system called THAAD to South Korea, which has infuriated China, the North's key diplomatic ally and crucial to efforts to persuade it to change its way. Pictured: A South Korea news broadcast of the missile test

A television displays news broadcast's infographics reporting on North Korea test-firing ballistic missiles, at a station in Seoul, South Korea, on Monday

THADD, or Terminal High Altitude Area Defense, systems are in place in Hawaii and Guam to defense against North Korea but this is the first time the US has deployed one in South Korea. Pictured: Military trucks at a US army unit in Dongducheon, South Korea

Trump has described North Korea as a 'big, big problem' and vowed to deal with the issue 'very strongly.' Pictured: Elements of the THAAD anti-ballistic missile defense system being deployed to Osan US Air Base in South Korea

Parts of the THAAD system arrived in South Korea by Monday, despite Beijing's proclamation that the US defense system is 'a clear, present and substantive threat to China's security interests.' Pictured: A South Korea sentry post at the Demilitarized Zone separating the Koreas

Military personnel walk past Japan's Ground Self-Defense Force missile interceptor unit, which was deployed to counter North Korea's launch of ballistic missiles

TERMINAL HIGH ALTITUDE AREA DEFENSE Terminal High Altitude Area Defense (THAAD) is a US army anti-ballistic missile system currently deployed in Hawaii and Guam. Operations to install THAAD in South Korea commenced Monday, March 6, following increased aggression from North Korea. South Korea and the United States agreed last year to install the THAAD system, which China has repeatedly denounced as a threat to its security. On installing THAAD in SK, the Pacific Command said: '(THAAD) contributes to a layered missile defense system and enhances the US-ROK Alliance's defense against North Korean missile threats.' The system is meant to intercept and destroy short and medium-range ballistic missiles during their final phase of flight. An AFP graphic illustrates THAAD's four-part response. First, radar detects a ballistic missile and the incoming threat is identified and engaged. The THAAD interceptor, which is composed of a booster and a 'kill vehicle,' is launched from the launcher, a vehicle that can carry up to eight interceptors. Fire control and communications support are on hand as the kill vehicle separates from the booster after launch. The interceptor uses kinetic energy to destroy the ballistic missile. The system is considered to be highly deployable and its manufacturer is Lockheed Martin. It is able to target missiles from both inside and outside the Earth's atmosphere. The system has had a perfect track record in flight testing since 2005, Lockheed Martin reports. Advertisement

South Korea officials said Monday that four missiles were fired from Tongchang County in North Pyongan province, travelling about 620 miles. Pictured: South Korean Defense Minister Han Min-koo

Pyongyang regularly issues threats against its enemies, and carried out two atomic tests and a series of missile launches last year, but Monday was only the second time its devices have come down in Japan's EEZ.

The launches came ahead of a trip by new US Secretary of State Rex Tillerson to the region.

Choi Kang, an analyst at the Seoul-based Asan Institute for Policy Studies, said the launch was a warning to Tokyo.

'North Korea is demonstrating that its target is not just limited to the Korean peninsula anymore but can extend to Japan at anytime and even the US,' he said.

Kim Jong-Un ordered his military 'to keep highly alert as required by the grim situation in which an actual war may break out anytime.' Pictured: Kim Jong-Un guiding the test-fire of a missile in an undated photo

NORTH KOREA'S MISSILE SYSTEM It is not yet clear which type of missiles were shot by North Korea into the Sea of Japan Monday. The nuclear-armed nation said Tuesday its missile launches were training for a strike on US bases in Japan. Three of the four missiles fired Monday came down provocatively close to US ally Japan, in waters that are part of its exclusive economic zone. North Korea could have as many as 1,000 missiles, a mixture of short-range, medium-range, intermediate-range and intercontinental-range. Intercontinental missiles, which can be shot more than 3,500 miles, would, depending on its longevity, be able to hit the United States from North Korea. Its program began in the 1970s with Scuds, or Soviet-developed missiles, that are believed to have been brought from Egypt. By the 1980s North Korea was building Hwasongs, or unique versions of the Soviet missile. The military was producing medium-range missiles, with a range of up to 2,000 miles, by the 1980s and had sold some of its artillery to other countries. More recently, the country has developed missiles with significantly wider ranges including the Taepodong-2, whose range could be as high as 9,300 miles though is more conservatively estimated to be 3,700. And it is believed that the country has been developing an even longer-ranging missile called the KN-08. The Pentagon believes the Asian nation could have six or more KN-08 missiles. Source: BBC Advertisement

Pictured is a satellite image take in 2013 of the Sohae Satellite Launching Station in Cholsan County, North Pyongan Province

Beijing has become increasingly frustrated with Pyongyang's nuclear and missile activities, and last month announced a suspension of all coal imports from the North until the end of the year - a crucial source of foreign currency.

Pyongyang wants to develop an intercontinental ballistic missile (ICBM) capable of reaching the US mainland - something Trump has vowed would not happen.

It has undoubtedly made progress in its efforts in recent years, although questions remain over its ability to master re-entry technology and miniaturize a nuclear weapon sufficiently to fit it onto a missile warhead.

Seoul said four missiles were fired from Tongchang County in North Pyongan province, travelling about 620 miles.