SINGAPORE, May 30 (Reuters) - Longer-dated U.S. Treasuries rallied in Asia on Tuesday as bond traders welcomed a deal to suspend Washington's borrowing limit and avert a debt default, should it pass Congress.

U.S. President Joe Biden and top congressional Republican Kevin McCarthy have reached a tentative deal to suspend the debt limit until 2025. A handful of Republicans have said they will oppose it, possibly making for a rocky journey through Congress though backers are confident it can clear in the next week.

Relief drove benchmark 10-year yields down 6 basis points at the open of trade in Tokyo to 3.7596%. Thirty-year yields fell 5.5 bps to 3.9207%.

Yields fall when bond prices rise, and the moves were the first reaction in the Treasury market since the debt deal was struck, owing to a holiday closing markets on Monday.

"Where there were the most distortions from the uncertainty was in the credit markets and in the Treasury bill market...I think on Tuesday, when the market reopens in the U.S., we should see those two distortions fixed," said Thierry Wizman, global currency and interest rates strategist at Macquarie in New York.

"But what this doesn't solve, is that along the whole Treasury curve yields have gone up recently. And I think they went up in anticipation that there will be a lot of issuance," he said, since Treasury needs to replenish its drained coffers.

T-bills had already rallied last week as a deal seemed close, especially those maturing early in June. Bid-offer spreads were wide in Asia, and nerves over the deal's passage through congress kept optimism in check.

Shorter-dated bonds also remain sensitive to the interest rate outlook and to growing doubts that the Federal Reserve has finished hiking.

Two-year yields were steady at 4.578%. (Reporting by Tom Westbrook. Editing by Sam Holmes)