David Cameron has promised an "all-out mission" to kick-start major infrastructure projects and get the economy moving.
The Prime Minister said he had given the go-ahead for two power plants in the north of England that will create 1,000 construction jobs.
He also welcomed news that BT will complete its roll-out of superfast broadband by 2014 - generating work for 500 more engineers. More announcements are expected over the coming months.
Writing in the Financial Times, Mr Cameron admitted that the eurozone crisis was having a "chilling effect" on global growth and he warned there were "no short-cuts to success".
But he urged people to be optimistic, warning that pessimism and fear "can become self-fulfilling prophecies".
"The eurozone crisis has had a chilling effect on major economies around the world, and has added to the unprecedented pressures facing the global economy," the premier wrote. "But, in spite of the difficulties, I am confident that we can both resolve the crises at hand and come through them with an economy that is stronger and fundamentally fairer."
He added: "I passionately believe that the global economy is presenting us with opportunities, not threats - and we must seize them."
Mr Cameron said he would be arguing at this week's G20 meeting in Cannes for "complete single-mindedness" on three fronts: confronting debts; strengthening economic competitiveness; and unlocking global trade.
Despite persistent calls from Labour for the coalition's cuts programme to be eased, he insisted the eurozone needed to show the "same resolve" at tackling deficits as Britain.
"The deal forged in Brussels marked very good progress," he wrote. "But in the coming weeks, the vital details need to be agreed - on the reinforcement of the bail-out, the recapitalisation of European banks, and the resolution of Greek's debt crisis."