TOKYO: Tokyo's benchmark Nikkei index on Tuesday morning rose past 20,000 for the first time in six weeks after Wall Street saw another record close and a weak yen lifted exporters.

The bellwether Nikkei 225 index climbed 1.45 percent, or 288.06 points, to 20,197.56 by the break, breaching 20,000 for the first time since early August.

The broader Topix index was up 1.33 percent, or 21.76 points, at 1,660.70.

"The solid US market and a weak yen explain most of today's rise," said Toshihiko Matsuno, chief strategist at SMBC Friend Securities.

Japanese politics may also be contributing to the gains, Matsuno said, as news reports say Prime Minister Shinzo Abe is considering a possible snap election next month as he sees recovering public support.

"As the ruling camp is unlikely to lose... it's not a negative factor but is not a big positive factor either," he told AFP, adding investors would need to watch public reactions as Abe does not have an actual reason to call an election now.

The dollar was trading at 111.51 yen, sharply up from 110.43 yen in Tokyo Friday before the market closed for a three-day weekend, as investors bet on rises in US interest rates.

Wall Street logged fresh records in advance of this week's meeting of the Federal Reserve, which is expected to announce a drawdown of its massive bond holdings.

The Fed is due to begin a two-day monetary policy meeting Tuesday and markets will be watching to see how Chair Janet Yellen describes recent trends in inflation for the world's largest economy, hoping for clues about the timing of the next interest rate hike.

In Tokyo trade, carmakers were lifted by the weak yen. Toyota rose 2.50 percent to 6,642 yen and Nissan was up 1.68 percent at 1,148 yen.

Nintendo jumped 5.69 percent to 40,430 yen.