Tokyo. America's ability to defend itself and its allies against North Korea is "beyond question," United States Ambassador William Hagerty said on Thursday (17/08), as he arrived in Japan to take up his post, and reaffirmed Washington's commitment to its alliance with Tokyo.

North Korea has said it was considering plans to fire missiles toward the US Pacific territory of Guam, although North Korean media on Tuesday said leader Kim Jong-un had delayed the decision while waiting for the next US move.

"The United States’ ability to defend itself is beyond question, the US ability to defend our allies like Japan is beyond question," Hagerty told reporters.

"Our alliance with Japan is ironclad. I expect to see us strengthening our position in the face of the increasing threat here in this region, and I also expect to see further involvement of Japan."

Hagerty added that he looked forward to seeing North Korea dial back its rhetoric, but reiterated that all options remained on the table to deal with Pyongyang.

In Beijing earlier on Thursday, Joseph Dunford, chairman of the US Joint Chiefs of Staff, said a peaceful option was the preferred solution, but that US President Donald Trump had told the military to develop viable military options.

Hagerty, a private equity executive, spent several years in Japan with the Boston Consulting Group and later served in the White House under former President George H.W. Bush.

Japan is a key US security ally in Asia and Japanese Prime Minister Shinzo Abe became the first world leader to visit President Donald Trump after his Nov. 8 election victory. The allies share concerns about China's growing regional military assertiveness.

However, Trump has criticized Japan, along with China and Germany, for having large trade imbalances with the United States and disappointed Tokyo by withdrawing the United States from a 12-nation Trans Pacific Partnership trade pact as well as the Paris climate accord aimed at combating climate change.

US officials have also said Japan's decision to hike tariffs on frozen beef imports from the United States could harm bilateral trade relations.

Hagerty succeeds Caroline Kennedy, an attorney and daughter of the late US President John F. Kennedy, who held the position from 2013 until Trump took office in January.

Reuters