LONDON, March 22 (Reuters) - Ukraine's sovereign dollar bonds jump on Friday after the International Monetary Fund signed off on a $880 million tranche of the country's $15.6 billion programme.

Adding to the momentum for bonds was an announcement on Thursday that the European Union could use proceeds from frozen Russian assets to help Ukraine within a few months under a plan that includes buying arms for Kyiv.

The 2028 dollar-denominated bond saw the biggest gains, up 2.4 cents to 34.06 cents at 1048 GMT, while longer maturities were up as much as 1.7 cents on the dollar.

"Moving forward with specific proposals to put to use the frozen Russia assets is positive, after months of talk about it, although we need to see the details," said Stuart Culverhouse, chief economist at London-based research firm Tellimer.

The IMF approval was largely expected, Culverhouse added, so "this may have already been discounted to some extent".

The latest IMF review brings the Fund's disbursements so far to $5.4 billion.

Upcoming talks with bondholders for a debt rework on Ukraine's private debt, and a report on a U.S. proposal to the Group of Seven on a special purpose vehicle to issue bonds backed by profits from frozen Russian assets, are other among "multiple factors" that explain why the bonds are rising, said Viktor Szabo, portfolio manager at Abrdn in London.

"And maybe also the fact that Ukraine has underperformed the very high yield complex this month," he added. (Reporting by Jorgelina do Rosario Editing by Karin Strohecker and Mark Potter)