* Nikkei up 0.7%, Topix 0.5%
* Steelmakers soar on brokerage upgrade
* Value shares outperform growth shares
* Japan govt stimulus supports cement companies
By Hideyuki Sano
TOKYO, Dec 5 (Reuters) - Japan's Nikkei share average bounced back on Thursday, with steelmakers leading the gains, after comments from U.S. President Donald Trump revived optimism about trade talks between the United States and China.
The Nikkei 225 index rose 0.71% to 23,300.09, back above the 25-day moving average of 23,275, a key technical level.
The broader Topix gained 0.48% to 1,711.41, just shy of the 13-1/2-month high of 1,719.57 hit late last month.
Topix Core 30, made up of top 30 firms on the main board, rose 0.43%, hitting a 14-month high.
Trump said negotiations with China were going "very well", fanning the positive mood sparked after a Bloomberg report that Washington and Beijing were closer to agreeing how many tariffs would be rolled back.
Steelmakers were the biggest beneficiaries of the latest surge in optimism, helped by rating upgrades from a brokerage.
The Tokyo Stock Exchange's steel and iron index jumped 4.2%, the biggest gain in 16 months and the top performer among 33 industry sub-indexes.
Nippon Steel soared 6.7%, JFE Holdings 5.2% and Kobe Steel 4.3%.
"Some of those shares are now traded at a P/E of around 40. It is not clear how much upside there is from here," said Hiroyuki Fukunaga, the head of Investrust.
Cement companies were another strong performer, also helped by Prime Minister Shinzo Abe having unveiled a $120 billion fiscal package.
Taiheiyo Cement leapt 5.4% and Sumitomo Osaka 4.0%.
Including steelmakers and cement firms, value shares fared better than growth-oriented shares, with the Topix value index rising 0.75% compared with a 0.2% gain in Topix growth .
Many technology shares also rode higher.
Taiyo Yuden gained 3.5%, TDK 2.5% and Lasertec climbed 2.0% to hit an all-time high.
Murata Manufacturing rose 1.6%, helped by a Nikkei business daily report that the company has developed new electronic parts to be used for 5G smartphones.
On the other hand, Nintendo ended 0.3% lower after announcing the previous day that it will launch Switch game consoles next week in China.
The shares had already rallied in recent sessions partly on expectations of such an announcement and hopes of an earnings boost from it.
The index of Jasdaq start-up firms edged up 0.1% to log its 10th straight day of gains.
Overall trading volume remained tepid, however, with the main board's turnover hitting just above 2 trillion yen, below the average over the past year of around 2.21 trillion yen.
Turnover has been below the average for more than a week. (Reporting by Tokyo Markets Team; Editing by Jacqueline Wong)