TOKYO, Jan. 28 (Xinhua) -- Japanese Prime Minister Yoshihide Suga spoke with new U.S. President Joe Biden via phone on Thursday, which was their first phone conversation since the American leader was inaugurated last week.

In the talks that lasted about 30 minutes, the two leaders affirmed the importance of Japan-U.S. alliance and discussed the situation of the Democratic People's Republic of Korea (DPRK) as well as COVID-19 response and climate change, among other issues, according to Japan's Foreign Ministry.

During the conversation, Suga welcomed Biden's decisions to return to the 2015 Paris Agreement on curbing carbon emissions and not to withdraw from the World Health Organization, while Biden invited the Japanese prime minister to take part in a summit on climate change slated for April 22, said the ministry.

After the talks, Suga told reporters, "I would like to deepen my personal relationship with President Biden and work to strengthen the Japan-U.S. alliance."

The Japanese leader also said that he hopes to visit the United States as soon as possible amid the challenges of containing the COVID-19 pandemic.

The issue of holding the Tokyo Olympics and Paralympics, however, was not discussed.