Seoul: South Korea will continue to closely consult with the United States to reach a resolution before the U.S. administration formalizes a tariff hike on Korea as threatened by President Donald Trump, Trade Minister Yeo Han-koo said Thursday, returning from a weeklong trip to the U.S.

According to Yonhap News Agency, Yeo's trip came after the U.S. president made a surprise announcement of a plan to raise "reciprocal" tariffs and auto duties on South Korea back to 25 percent, citing a delay in South Korea's legislative process supporting the implementation of the countries' bilateral trade deal that had lowered most U.S. tariffs on South Korea to 15 percent. Earlier reports said the U.S. administration plans to soon publish a Federal Register announcing the envisioned tariff hike.

"What is important is whether the U.S. will immediately raise tariffs upon issuing a Federal Register or whether there would be a grace period of about one to two months," Yeo told reporters at Incheon International Airport. Yeo insisted such a publication was "unnecessary" since Seoul is continuing to take "good faith efforts" to implement the tariff agreement.

"Since we still have time for consultations, the government will continue to engage in close discussions with the U.S. and do our utmost to reach a conclusion that best serves our national interest," he added. During his trip, Yeo met with the deputy U.S. Trade Representative (USTR) and some 20 U.S. lawmakers to reaffirm Seoul's commitment to legislating a special bill to implement the trade deal and address non-tariff issues related to digital regulations and others, according to the Ministry of Trade, Industry and Resources.

Yeo welcomed the rival parties' decision on Wednesday to establish a special committee to advance the U.S. investment bill within a month, saying it would help resolve the ongoing trade tensions with the U.S. "While it is difficult to say with certainty how the U.S. will accept this move, I believe the National Assembly's commitment to moving forward with the legislative process through the rival parties' agreement will definitely be helpful as Washington has cited the delay in the legislation of the U.S. investment bill as the biggest reason for its tariff hike plan," he said.