SEOUL: South Korea and Vietnam will pledge deeper economic and strategic cooperation when their leaders hold a summit on Monday (Aug 11) as the former Cold War-era foes seek to leverage their business ties to navigate a challenging global trading environment.South Korean President Lee Jae Myung hosts Vietnamese leader Lam To as his first state guest since taking office on Jun 4 and will discuss promoting trade and investment in the Southeast Asian country, Lee's office said.Lam, who is the Vietnamese Communist Party general secretary, leads a delegation of industry, trade, foreign and technology ministers and senior party and parliament members on the four-day state visit.The countries plan to sign at least 10 memoranda of understanding at the summit meeting, pledging cooperation in nuclear and renewable energy, monetary and financial policies, and science and technology, Lee's office said.The rare visit by the Vietnamese leader is expected to contribute to a favourable condition for South Korean businesses to invest in major infrastructure and nuclear energy projects planned in Vietnam, it said.A number of major South Korean companies including Samsung Electronics have used Vietnam as an export hub, benefiting for years from lower labour costs, generous tax incentives and Hanoi's numerous free trade pacts with dozens of countries.But the trade policy of US President Donald Trump, who imposed sweeping new tariffs on the Asian countries in recent weeks, has increased uncertainty over future business commitments, with Vietnamese official data showing a slowdown in new investment.South Korean companies have been cited as potential investors in Vietnam's planned nuclear energy, LNG power plants and high-speed rail projects.Trump has imposed a tariff rate of 15 per cent for South Korean goods and 20 per cent for imports from Vietnam.