South Korea’s Kospi opened at a fresh record Monday, leading gains in Asia-Pacific markets amid rising oil prices and escalating tensions between the U.S. and Iran.

President Donald Trump’s rejection of Tehran’s latest proposal to end the war, however, stoked worries over an elongated Middle East conflict.

Iran submitted a new proposal to U.S. negotiators focused on ending the Middle East conflict. Iran’s semi-official Tasnim news agency said that the counteroffer called for an end to the war on all fronts and the lifting of sanctions on Tehran, citing an informed source.

However, Trump said he did not like Iran’s response and called it “TOTALLY UNACCEPTABLE!” in a Truth Social Post.

Meanwhile, Israeli Prime Minister Benjamin Netanyahu said Sunday that the war with Iran was “not over,” as the U.S. and Israel still aim to curb Tehran’s nuclear ambitions.

Netanyahu’s comments come ahead of Trump’s trip to China later this week, where he’s expected to meet with Chinese President Xi Jinping. The war and the subsequent closure of the Strait of Hormuz by Iran have spiked global energy costs and sharply raised gas prices in the U.S.

The West Texas Intermediate futures for June was 3.94% higher at $99.18 per barrel as of 9:32 p.m. ET. Brent crude futures for July rose 3.49% to $104.83 per barrel.

South Korea’s Kospi gained 4.70% after opening to a fresh record, while the small-cap Kosdaq was 0.30% lower. Index heavyweight SK Hynix rose 10.74%, tracking U.S. chip-related equities which surged Friday.

Japan’s Nikkei 225 was in choppy trade and was marginally lower, while the Topix gained 0.19%. Nintendo shares fell 5.54%, as investors digested news that the game developer will hike Switch 2 prices while expecting a decline in console sales.

Australia’s S&P/ASX 200 was 0.83% lower.

China’s CSI 300 added 0.58%, while Hong Kong’s Hang Seng index declined 0.48%. Investors were also assessing data showing that China’s consumer and producer inflation rose more than expected in April, driven by higher commodity costs linked to the Middle East conflict.