On Tuesday, U.S. President Donald Trump warned North Korea in his speech to the U.N. that the United States would "totally destroy" the country if threatened.
At a time of national crisis over North Korea, Japanese voters may see it as a "cynical and opportunistic move" created to divert attention from a series of scandals that weighed on Abe's popularity, warned Sano.
Trump's explicit mention in his speech of the North's abduction of Japanese in the 1970s and 1980s was a major demonstration of the closeness between the two leaders.
Abe's speech came a day after President Donald Trump threatened to "totally destroy" North Korea if it attacks the US or its allies.
Chief Cabinet Secretary Yoshihide Suga has said: "We greatly appreciate President Trump's approach to changing North Korea's policy stance, denuclearising the country and calling on the worldwide community, including China and Russian Federation, for their cooperation toward strengthening pressure on North Korea". South Korean President Moon Jae-in has repeatedly called on North Korea to enter into dialogue over its nuclear program.
The Abe administration bristled at South Korea's decision Thursday to send humanitarian aid to North Korea through United Nations agencies, with Japanese officials quoting Abe as having "called for South Korea to act with caution" in the three-way summit.
China appeared to heed Washington's call Thursday, with Trump expressing gratitude for what he said was the Chinese central bank's decision to order commercial banks to stop doing business with North Korea.
Political tensions intensified further on Friday over Prime Minister Shinzo Abe's envisaged breakup of the House of Representatives next week for a snap election in October of the lower chamber of the Diet.
Abe is expected to hold a news conference after meeting with party executives and will likely put pledges to spend on education and child care, stay tough on North Korea and revise the constitution at the forefront of his campaign.
Nevertheless, one fifth of those polled said they were still undecided, potentially opening the door for gains by a new party formed by allies of the popular mayor of Tokyo Yuriko Koike, which will field dozens of candidates.
Mr Abe is thought to be wanting to capitalise on a role of strong leadership in a time of crisis with North Korea.