After fluctuating last week on worries about a possible global trade war and Donald Trump's removal of moderate voices in his cabinet, regional equities are struggling to maintain a run of gains.
Investors are also keeping an eye on Washington after another outburst by Trump against a probe by special counsel Robert Mueller into claims of Russian meddling and collusion with the tycoon's campaign in the 2016 presidential election.
There are fears in some quarters that Trump is planning to fire Mueller. Greg McKenna, chief market strategist at AxiTrader warned that if he did, then "all heck could break loose on markets".
In Japan, the Nikkei finished 0.9 percent lower as Abe and Finance Minister Taro Aso are embroiled a scandal over the cut-price sale of government land to a supporter of the prime minister to open an elementary school.
The finance ministry has admitted altering documents related to the deal.
A weekend poll by the Asahi Shimbun daily found public support nosediving 13 percentage points from a month ago to 31 percent, the lowest since Abe took power in December 2012. Abe denies any wrongdoing.