Prime Minister Shinzo Abe welcomed on Thursday U.S. President Donald Trump's plan to call for an "unprecedented" boost in defense spending.

"Strengthening the Japan-U.S. alliance through the increase (in defense spending) will be positive for the peace and prosperity of not only Japan and the United States but also the Asia-Pacific region," Abe said.

"Mr. Trump has announced that the United States will have enough military power to firmly ensure its presence in the Asia-Pacific region," Abe said in a House of Representatives Budget Committee session.

In his first address to Congress since taking office on Jan. 20 on Tuesday, Trump vowed to rebuild the U.S. armed forces, saying his budget blueprint for the next fiscal year starting in October will call for an unprecedented level of increase in defense spending.

The president made the pledge a day after the White House unveiled the first details of Trump's budget plan featuring a $54 billion, or 10 percent, expansion in defense spending from the level in the current budget year.