NEW YORK (Reuters) - Desperate fans are paying thousands of dollars for tickets to watch Ireland's Conor McGregor attempt to become the first fighter to hold two Ultimate Fighting Championship (UFC) belts concurrently on Saturday.

The green-clad Irish fans of brash featherweight champion McGregor were out in force in mid-town Manhattan on Friday ahead of his lightweight title fight against Eddie Alvarez in UFC 205 at Madison Square Garden on Saturday.

But with UFC president Dana White telling Fox Sports that the event had broken the previous gate record of $13.5 million at the venue - set by the Lennox Lewis v Evander Holyfield heavyweight boxing bout in 1999 - many fans have been left empty-handed.

Mixed marital arts was banned in the state of New York for almost 20 years and tickets for the first event since the suspension was lifted were on sale via online secondary markets for up to $19,000, over 10-times face value.

One person who should have no problem getting a ticket is U.S. president-elect Donald Trump.

"Donald originally told me that he would come to the event if he won," said White, who endorsed Trump for the presidency at the Republican National Convention in July.

"I don't think Donald really realized what his duties were going to be had he won," he added, adding that he doubted Trump would be able to make it.

(Reporting by Philip O'Connor, editing by Ed Osmond)