The release of three U.S. citizens held in North Korea should not be a condition for the planned summit between U.S. President Donald Trump and North Korean leader Kim Jong Un, Sweden's foreign minister said on Monday.

The United States has no embassy in Pyongyang and relies on Sweden, the so-called U.S. protecting power there, to do consular work, especially to help Americans in trouble.

Asked about the three Americans, Swedish Foreign Minister Margot Wallstrom said: "I don't want to have those elements involved in all of this ... this is not a time to put up a lot of conditions and preconditions."