Tokyo - Tokyo stocks rose on Tuesday with investors encouraged by Wall Street rallies and Japan's Takeda surging on reports that the drugmaker would make a formal offer to buy Ireland's Shire.
The benchmark Nikkei 225 index gained 0.18% to close at 22 508.69 while the broader Topix index was up 0.37% at 1 779.82.
"Investors welcomed a sign of recovery on Wall Street," said Shinichi Yamamoto, broker at Okasan Securities in Tokyo.
"But they are still cautious about uncertain factors, including the Iran issue," Yamamoto told AFP.
President Donald Trump is expected to announce later on Tuesday whether he will re-impose US sanctions on Tehran, potentially throwing the entire Iran nuclear deal into question.
European leaders and diplomats - including Britain's Foreign Secretary Boris Johnson, who was in Washington on Monday - have been pleading with the United States to retain the core of what Trump called a "flawed" accord.
In the 2015 pact, major powers agreed to ease some sanctions on Iran in exchange for greater scrutiny of its nuclear activities.
On Wall Street, stocks finished higher on Monday with technology shares leading the market and oil-linked shares gyrating.
The tech-rich Nasdaq Composite Index gained 0.8%, while the Dow Jones Industrial Average gained 0.4%.
In Tokyo, Takeda surged 3.99% at ¥4 638 hours ahead of a deadline for the Japanese pharmaceutical company's takeover bid for Irish pharmaceutical firm Shire.
Immediately after the market closed, Takeda announced a firm acquisition offer worth $62.5bn for Shire, after a series of unofficial bids were turned down.
Panasonic rose 0.37% to ¥1 596.5 while SoftBank gained 0.33% to ¥8 489, with Honda up 0.30% at ¥3 630.
The dollar fetched ¥108.94 on Tuesday afternoon, up from ¥109.88 in New York late on Monday.
* Sign up to Fin24's top news in your inbox: SUBSCRIBE TO FIN24 NEWSLETTER