The US military said Monday it had deployed stealth fighters to South Korea as part of an ongoing joint military exercise that has triggered further military threats from North Korea.

The US military said Monday it had deployed stealth fighters to South Korea as part of an ongoing joint military exercise that has triggered further military threats from North Korea.

Two F-22 Raptor fighters arrived in the South on Sunday to participate in the annual "Foal Eagle" exercise that will last until April 30,” AFP quoted a spokesman for the US forces in South Korea as saying.

The jets were reportedly flown out of the US air base in Okinawa, Japan.

In this context, South Korea's new president promised on Monday a strong military response to any North Korean act after the latter declared it had entered a "state of war" with the South, and warned Seoul and Washington that any provocation would swiftly escalate into an all-out nuclear conflict.

President Park Geun-Hye's warning came as North Korea's parliament was set to hold its annual session and a day after ruling party leaders vowed to enshrine Pyongyang's right to nuclear weapons in law.

The annual single-day session of the Supreme People's Assembly usually scores low on important policy announcements -- its role largely limited to unanimously pushing through pre-decided budgets and personnel changes.