Stocks all around the Asia Pacific region plummeted on Monday amid rising concerns for the United States and Iran as investors expressed fears of potential continuous retaliation from the latter.

According to CNBC, South Korea's Kospi shed 0.83 percent, the Australian ASX 200 slumped by 0.72 percent, and Japanese shares also dropped, with the Topic index dropping 1.48 percent, and the benchmark Nikkei 225 leaving behind 1.85 percent during early trading.

While the Australian market's decline has been largely directed to the devastating bushfires that already killed at least 18 people and millions in animals across different suburbs, the slump in other markets in Asia has been blamed on U.S. -Iran tensions.

Sentiment has been damaged since January 3, when Iran's top military commander, Qasem Soleimani, was killed in a U.S. airstrike in Baghdad. Oil prices have also been affected since then, with prices soaring by up to three percent before the weekend.

As of Monday, the global benchmark Brent reached $69.76, with 1.69 percent added to the previous price. American crude futures were also surged by 1.35 percent. Each barrel now costs $63.90.

Some global market experts warned that oil prices might keep hiking if the U.S. and Iran continue with threats of new sanctions from the former and retaliation from the latter.

On Saturday night, U.S. President Donald Trump said in a tweet that should the Iranian side strike American assets or any American, his country will set eyes on targeting 52 sites in the Middle Eastern nation.

In an interview with CNN, U.S. Secretary of State Mike Pompeo did not directly answer questions regarding Trump's tweets. Instead, he said the country will "do the things that are right and the things that are consistent with American law."

Back in Iran, protesters have been calling out the White House for the death of Soleimani. Cultural experts have also argued that Trump's threats on Iranian cultural heritage sites, if carried out, may be a war crime.

Reports have also emerged regarding the alleged opposition of American officials on Trump's suggestion of targeting Iranian cultural sites. An official who worked in the past with the Barack Obama and Trump administrations said that in "principle," the U.S. should not attack "the culture sites of any adversary."

Meanwhile, residents of Baghdad said on Monday that they heard three explosions within the Green Zone, where the U.S. Embassy and Iraq's central government are located, the Associated Press reported.

No official confirmation has been made from Iranian officials but some believe the explosions were rockets and mortars that hit the said area. It remains to be seen whether the two sides will discuss a potential truce.