NEW YORK, Dec 1 (Reuters) - The Group of Seven (G7) nations are "very, very close" to agreement on a $60 a barrel price cap on Russian seaborne oil with an adjustment mechanism to keep the cap at 5% below the market price, a senior G7 coalition official said Thursday.

The official told reporters that the deal should be finalized in coming days or Monday at the latest, and expressed confidence that the price cap would limit Russia's ability to fight its war against Ukraine.

G7 officials had been in close touch with markets about the price cap, and they seemed "pretty comfortable" with the mechanism, which is aimed at limiting Russian oil revenues while maintaining adequate supplies for the global market, the official said. (Reporting by Andrea Shalal and David Lawder; editing by Diane Craft)