Meanwhile, the U.S. Federal Reserve is scheduled to release a statement later in the day around 1800 GMT, while Philippines and Indonesia's central banks are set to meet on Thursday to review monetary policy.
Mario Draghi said on Tuesday the European Central Bank will ease policy again if inflation fails to accelerate, sparking hopes that the U.S. Fed would also follow suit.
"With increased odds of the Fed easing, we don't think Asian central banks will resist easing pressure for too long," ING analysts said in a note.
Analysts, however, expect the central banks of Indonesia and Philippines to hold steady and enact a "dovish pause", awaiting further data before making any big moves.
Sentiment was also supported by U.S. President Donald Trump's confirmation that he would meet his Chinese counterpart Xi Jinping at the G20 summit in Japan later this month, indicating that trade talks between the two countries would restart after a long lull.
Leading the gains in the region, Singapore stocks jumped 1.5% to their best closing level since May 10. Large caps were the biggest boost, with lenders DBS Group Holdings and United Overseas Bank adding 2.5% and 2.1% to the index, respectively.
Thai stocks rose 1.3% to hit their highest close in eight months. Industrials and energy stocks lifted the index, with Airports of Thailand PCL and PTT PCL closing up 8.1% and 1.1%, respectively.
Indonesian shares ended 1.3% firmer, with material and financial stocks dominating the gains. Bank Danamon Indonesia Tbk gained 8.3%, after marking its best session in nearly a year.
The Malaysian index extended gains, buoyed by Malaysia Airports Holdings, while agriculture and food processor Sime Darby Plantation ended 3.7% higher.
Philippine stocks were supported by strength in industrials, while Vietnam's index was propelled by heavyweight property stocks.
(Reporting by Rashmi Ashok in Bengaluru, Editing by Sherry Jacob-Phillips)
By Rashmi Ashok
