TOKYO, Dec 17 (Reuters) - Long-term Japanese government bond yields rose slightly on Thursday in anticipation of more fiscal spending both domestically and in the United States to prevent the COVID-19 pandemic from slowing economic growth. Japan will increase issuance of new government bonds next fiscal year to fund a record budget exceeding $1 trillion, the Nikkei newspaper reported. U.S. lawmakers are edging closer toward an agreement on a new aid package, while Japan’s cabinet earlier this week approved an additional extra budget as major countries grapple with a third wave of virus infections. The long end of the curve also got a boost after the U.S. Federal Reserve refrained from extending the duration of debt it buys, disappointing some dealers who had expected it to reign in a recent rise in long-term yields. Benchmark 10-year JGB futures fell 0.06 point to 152.03, with a trading volume of 12,598 lots. The 10-year JGB yield was flat at 0.005%. The 20-year JGB yield was also flat at 0.385%. At the long end of the curve, the 30-year JGB yield rose 0.5 basis point to 0.630%, while the 40-year JGB yield climbed 0.5 basis point to 0.680%. The five-year yield was flat at minus 0.120%. At the short end, the two-year JGB yield held steady at minus 0.135%. (Reporting by the Tokyo markets team; Editing by Subhranshu Sahu)