By Davide Barbuscia

NEW YORK, April 22 (Reuters) - U.S. Treasury long-term yields declined on Tuesday, reversing some of Monday's bond selloff, as fears that President Donald Trump's trade policies could trigger a U.S. economic slowdown provided some demand for U.S. government bonds.

Yields, which move inversely to prices, had jumped on Monday as Trump's calls to remove Federal Reserve Chair Jerome Powell caused market concerns over U.S. economic stability and institutional strength.

While those worries continued to agitate markets on Tuesday, bonds benefited from some safe-haven demand due to continued fears of an impending hit to U.S. economic activity because of Trump's punitive tariffs on key U.S. trade partners.

"You have a push and pull dynamic," said Nathan Thooft, chief investment officer and senior portfolio manager at Manulife.

"You have forces that are potentially negative for Treasuries, as in higher yields driven by the U.S. losing some of its glamor and glitter [that come from] ... being the primary if not sole safe haven, but at the same time Treasuries are still used inside the U.S. as well as by many people outside the U.S., as a source of safety," he said.

While light on economic data, Tuesday's session will see investors focusing on remarks from Fed officials after Trump in recent days accused the Fed chair of being slow to ease rates and hinted that he might try to remove him.

It remains to be seen whether Trump would legally be allowed to remove Powell, but the attacks could undermine market confidence in the central bank's ability to act independently.

Federal Reserve Bank of Philadelphia President Patrick Harker said trust in the central bank was one of its greatest powers. This credibility has built up over time “by being politically independent and as objective as human beings can be,” he said.

The attacks on the Fed could exacerbate existing concerns over Trump's erratic policymaking and its impact on foreign investor appetite for Treasuries, analysts said.

"With increasing rhetoric from the administration admonishing the Fed to cut rates and the markets entertaining intensifying discussions about the possibility of replacing the Fed chair, we don’t expect a rush back into the market from abroad," BNY's Americas Macro Strategist John Velis said in a note. "The haven status of such assets is increasingly in question."

Benchmark 10-year yields US10YT=RR were last at 4.387%, nearly three basis points down from Monday, while 30-year yields US30YT=RR declined by about three basis points to 4.881%. Two-year yields US2YT=RR were last at 3.789%, up from 3.752% on Monday.

Later on Tuesday, the Treasury will auction $69 billion in two-year notes, part of a total of $183 billion in Treasury debt issuance this week.

(Reporting by Davide Barbuscia)

((Davide.Barbuscia@thomsonreuters.com; +1 917 285 3067;))