Case for Scottish independence doesn't stack up: Osborne

British finance minister George Osborne reiterated his stance on Scotland's campaign to break away from the U.K, stating that the case for independence simply doesn't make economic sense.

"From my recent visit to Edinburgh, what's clear to me is that the economic arguments for independence don't stack up," Osborne told CNBC at a press briefing in Singapore on Monday.

(Read more: Scotland's Salmond: blocking pound will hurt UK)

"And the assertion by the nationalists that Scotland could share the pound with the rest with the U.K. is simply not the case. The things required to make a currency union work wouldn't be in place," he added.

The Scottish government has argued that keeping the pound made sense for both Scotland and the rest of the U.K. But Osborne has made it clear that he does not think the government's currency union plan is viable.

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"[Alex] Salmond's (head of the separatist Scottish National Party) response to the kinds of things that have been said not just by me, but by independent commentators is frankly pretty thin. He's increasingly looking like a man without a plan," he said.

Scotland will vote on whether to leave the U.K. on September 18, with polls showing just over one third favor independence, according to Reuters.

UK set to raise its economic "game"

While Britain's economic recovery is gaining pace, there is more work to be done to broaden the drivers of growth, Osborne said.

(Read more: Britain says Scotland would lose the pound if it leaves UK)

"You see the recovery at the moment driven by consumer spending, now that you would expect at this point of the recovery but we've now got to make sure we got into the next stage of the recovery, and see more investment and exports," he said.

"We've got an opportunity in the budget I'll present next month to make sure government policy stands behind investment and exports," he added. "I'm not a finance minister resting on my laurels. I'm saying the job's not done; we've got more to do. I think Britain will raise its game."

David Cameron's message to Scotland
David Cameron's message to Scotland

The U.K. economy recorded its fastest annual growth rate since the start of the financial crisis in 2013, with full-year growth up 1.9 percent from just 0.3 percent in 2012.

Britain's stance on Ukraine

Discussing his take on developments in Ukraine, Osborne said the U.K. stands ready to provide financial support to the Eastern European country ravaged by a political crisis and economic uncertainty.

(Read more: Carney to Scotland: Be careful what you wish for)

Ukraine's parliament on Saturday voted to remove President Viktor Yanukovych after a week of bloodshed and set an early election for May 25. Ukraine plunged into a crisis in November after Yanukovych rejected a deal to deepen ties with the European Union (EU), triggering protests.

"We should be there ready to provide financial assistance through organizations like the IMF (International Monetary Fund); and of course a lot of this will take the form of loans and the like. But it's very early days. You have to have a legitimate political authority that we can deal with. We are in the hours of the unfolding political situation," he said.

—By CNBC's Ansuya Harjani. Follow her on Twitter @Ansuya_H