Praful Patel, a vice president at the bank, said the South Asian country needed to make painful adjustments to higher global prices for oil, commodities and foodstuffs or risk a slowdown.
"There is not yet a crisis, but the economic picture for Pakistan is not good," Patel said. "There is a good economic foundation, but the growth can only continue if Pakistan adjusts to the new global reality."
Patel issued a statement after a three-day visit to Pakistan, which included talks with leaders of the new Government taking power after eight years of military rule under former President Pervez Musharraf.
Musharraf, who seized power in a 1999 coup, guided Pakistan from the brink of bankruptcy to multiyear economic growth.
A United Nations report released on Thursday said that Pakistan's economy was expected to grow at 6.5 percent this year, despite uncertainty about stability of the country, which faces rising Islamic extremism as well as a bumpy transition back to democracy.
But some economists warn the current expansion is heavily reliant on a boom in consumer spending and money sent home by Pakistanis working abroad and that the country produces too few high-value exports.
In the short-term, there is particular concern about the Government's rising budget deficit and a shortfall in the balance of payments. Both are putting downward pressure on the Pakistani currency, the rupee.
Patel noted that foreign investment and remittances have kept pace and that the stock market has posted gains. The Karachi Stock Exchange's benchmark index closed at a record on Thursday.
However, he forecast that the government would miss its targets for the budget and current account deficits as well as for foreign exchange reserves.
The caretaker administration that quit office this week had begun reducing subsidies on fuel prices that have bitten deeply into the government's coffers. The new government must decide where to cut spending and is reportedly eyeing the military budget for possible reductions.
The World Bank said its team discussed changes in oil imports, taxation and "prioritization of expenditures."
"Any adjustment will be painful," said Patel. "But there must be an appropriate safety net for the poor." He said that could include direct cash transfers, a mechanism used to relieve people hit by Pakistan's massive 2005 earthquake.
Pakistan's new prime minister, Yousaf Raza Gilani, is expected to announce steps to address problems including high food prices and energy shortages when he makes his first policy speech in Parliament on Saturday.
"If action is not taken, the economy will start to falter, but with the right policies and strong support from multilateral and bilateral partners, we believe the high growth and poverty reduction path can be maintained in Pakistan," Patel said.