* Finmin Kan: 2-3 years too long to beat deflation
* Bank minister Kamei: BOJ should underwrite govt debt
* BOJ Shirakawa repeats beating deflation most important
* BOJ's next likely step is to expand fund supply -analysts (Adds output gap figures, details)
By Leika Kihara and Rie Ishiguro
TOKYO, March 1 (Reuters) - Japan's finance minister said he wants the country to pull out of deflation by the end of this year, setting a deadline much earlier than the Bank of Japan's forecast as he ratchets up pressure for further monetary easing.
The country's outspoken banking minister Shizuka Kamei went further, saying the central bank should directly underwrite public debt to finance government spending.
"Escaping deflation is difficult so we won't see an immediate improvement such as in several months. But taking two to three years would be too long," Finance Minister Naoto Kan told a lower house financial committee on Monday.
"Hopefully, we want Japan to see prices turn positive by the end of this year," he said, adding that he hopes the BOJ will work with the government in overcoming deflation.
The BOJ forecasts three years of deflation until March 2012 and has said it is committed to fighting deflation, but has offered few clues on what it might do in the future. Core consumer prices fell 1.3 percent in the year to January, marking the 11th straight month of annual declines.
The government, hobbled by ballooning public debt, has been pressuring the BOJ to support the fragile economy even as most other major central banks mull rolling back stimulus steps put in place during the global financial crisis.
With the economy barely out of recession and supply still outstripping demand by a huge margin, analysts do not expect Japan to escape deflation any time soon.
The BOJ buckled under pressure last year so further action in response to government calls might not deal a severe blow to its reputation. But yielding to demands that appear unrealistic could put the BOJ's credibility on the line.
"It's impossible for prices to turn positive by the year-end. I don't think any economists expect this to happen," said Akiyoshi Takumori, chief economist at Sumitomo Mitsui Asset Management.
"If the BOJ were to cave in to such government pressure, it would dent market confidence in the central bank."
Analysts say while the BOJ will want to save its ammunition for when sharp rises in the yen hurt the economy, it may have to act around June, when government pressure for more steps could escalate ahead of upper house elections expected in July.
They say the most likely next step is for the BOJ to expand its fund-supply operation adopted in December, in which it lends to banks at 0.1 percent, from 10 trillion yen ($112.4 billion) or to extend the duration of loans from three months.
BOJ Governor Masaaki Shirakawa said the central bank will stick to very easy monetary policy to beat deflation, which he sees as the most important goal for monetary policy.
BOJ URGED TO MONETISE DEBT
While markets did not react directly to the remarks by Kan and Kamei, expectations that the BOJ could ease policy further helped limit losses on government bond futures.
Deflation hurts the economy as households put off spending on hopes that prices will fall further, forcing companies to cut prices to lure consumers.
Kan reiterated his view on Monday that Japan should aim for inflation of "1 percent or somewhat higher", a goal that has proved elusive in nine of the past 10 years.
The call for 1 percent inflation is basically in line with the BOJ's view of long-term price stability as annual inflation of 2 percent or less, with 1 percent as an ideal level.
But the mere mention by Kan of such a goal in effect raises pressure on the central bank, which yielded to government criticism by calling an emergency meeting in December to announce it was pumping more cash into the banking system.
"Kan may be putting more pressure on the BOJ to accept his calls for setting an inflation target as the central bank has not given favourable replies so far," said Hirokata Kusaba, a senior economist at Mizuho Research Institute.
The BOJ is opposed to setting a rigid inflation target for fear of tying its hands on monetary policy, particularly with increasing signs that deflation will persist.
Japan's narrowest measure of consumer inflation matched a record annual fall in January in a sign weak demand was forcing companies to cut prices to lure consumers.
The output gap stood at minus 6.1 percent in the fourth quarter, narrowing from July-September but showing excess output capacity was weighing on prices, data showed on Monday.
Kamei called for even more drastic action, urging the BOJ to underwrite public debt, a move the BOJ is strongly opposed to for fear of triggering runaway inflation in the long term.
"I suggest the BOJ directly underwrite government bonds to help the government come up with financial resources," Kamei told the same parliamentary committee.
Kamei has much less influence on monetary policy than Kan as he cannot send a representative to sit on BOJ policy meetings.
The BOJ currently buys 21.6 trillion yen of long-term government bonds outright from the market each year. It has been hesitant to raise that purchase amount, let alone buy debt directly from the government.
While some analysts say the BOJ may increase its outright bond purchases if yields shoot up on worries about Japan's worsening finances, few expect the central bank to go as far as to directly underwrite debt. ($1=88.93 Yen) (Editing by Michael Watson)