The dollar jumped to a 3-week high on Tuesday while stock markets in Asia were nervous and jittery as a historic U.S.-North Korea summit got underway in Singapore, raising some hopes it could pave the way to ending a nuclear stand-off on the Korean peninsula.

U.S. President Donald Trump and North Korean leader Kim Jong Un smiled for cameras after 41-minutes of one-on-one talks, just months after they traded insults and tensions spiraled in the region over the latter’s nuclear programs.

Yet, there was some unease among investors about the outcome of the talks given the tense relations between the two nations. The combatants of the 1950-53 Korean War are technically still at war, as the conflict, in which millions of people died, was concluded only with a truce.

Trump and Kim are participating in a one-on-one meeting, with translators only, followed by an expanded meeting including their top advisers and a working lunch. According to the White House, the discussions between the U.S. and North Korea are "ongoing and have moved more quickly than expected."

The summit announcement came in March after several months of unprecedented cordial diplomacy between South and North Koreas, which had been adversaries for decades.