South Korea to buy 'billions of dollars' of US weapons: Trump

After a summit with South Korean President Moon Jae-In, Trump also said the US -- the South's key security guarantor -- had agreed to remove a warhead weight limit on Seoul's ballistic missiles. 

Trump arrived in Seoul on Tuesday for a two-day visit as part of his Asia tour amid high tensions over North Korea's weapons drive. 

Trump said the South -- a key Asian ally which hosts 28,500 US troops -- would be buying a large amount of US weapons "whether it's planes, whether it's missiles, no matter what it is". 

"South Korea will be ordering billions of dollars of that equipment, which for them makes a lot of sense and for us it means jobs, reducing our trade deficit with South Korea," he said. 

Moon confirmed the planned purchases which he described as "essential", saying Seoul had agreed to begin talks to buy US strategic assets to enhance Korea's defence capabilities. 

Under the existing missile pact between the US and the South, Seoul has only been allowed to develop warheads as heavy as 500 kilograms for its ballistic missiles. 

The US instead offers the South a "nuclear umbrella" against potential attacks, but Seoul has sought to remove the limit in recent years amid the growing missile threat from the North. 

The allies had agreed in principle to do so in September following the North's latest nuclear test, by far its most powerful to date. 

Moon, noting "ever-growing threats" from the North's missiles and nuclear weapons, said Tuesday the two allies had reached a "final agreement" to remove the restriction. 

"We also reaffirmed our stance to put maximum pressure and sanctions on the North until it... comes foward for genuine negotiations," he told reporters.