NEW YORK, April 15 (Reuters) - The U.S. dollar rose slightly on Wednesday and was on track for its first gain in eight sessions after falling to levels not seen since the start of the Iran war, as investors gauged the likelihood that peace talks would resume shortly.

U.S. President Donald Trump said the war with Iran could end soon, telling the world to watch out for an "amazing two days," while U.S. forces imposing a blockade turned back vessels leaving Iranian ports.

A senior official said on Wednesday, however, that the U.S. has not formally agreed to the extension of its ceasefire with Iran, although there is continued engagement between the two countries to reach a deal.

The war has effectively shut the Strait of Hormuz, a crucial waterway for a fifth of global oil and gas shipments as well as other key products such as fertilizer, since the U.S.-Israel attacks on Iran began on February 28, sending oil prices surging and igniting concerns about the hit to global growth and inflation.

"We're trying to figure out if negotiations are going to continue, if the ceasefire will continue, and if ultimately tensions can be established as solidified or eased, but no one knows exactly where things are going," said Juan Perez, senior director of trading at Monex USA.

"Not only are we at the mercy of the headlines over the conflict, but now the focus is going to be on economic growth."

DOLLAR INDEX EDGES HIGHER

The dollar index, which measures the greenback against a basket of currencies, was up 0.03% on the day to 98.11 after climbing to 98.286, with the euro off 0.01% at $1.1794.

U.S. crude fell 0.05% to $91.23 a barrel and Brent rose to $94.81 per barrel, up 0.02% on the day.

The European Central Bank is not yet in position to determine if the current oil price-driven inflation shock is transitory or if it requires it to raise interest rates, ECB President Christine Lagarde said on Tuesday.

The dollar index had dropped as low as 97.968 on Tuesday, its weakest level since March 2, the first trading day after the U.S.-Israeli war with Iran began, but investors said robust demand for U.S. assets and waning prospects for U.S. interest rate cuts should buttress it against sharper declines.

The seven-session losing streak for the dollar is its longest since a nine-session skid that ended on December 3, when investors were largely expecting at least two rate cuts from the Federal Reserve this year.

ECONOMIC DATA IN FOCUS

U.S. Treasury Secretary Scott Bessent told CNBC the economy will be slower this quarter amid the Iran war, but that it is in good shape and will rebound, adding that oil prices do not appear to be weighing on inflation expectations.

The U.S. Labor Department said import prices rose 0.8% last month after a downwardly revised 0.9% gain in February, short of the 2% rise forecast by economists polled by Reuters. In the 12 months through March, import prices shot up 2.1%.

Cleveland Fed President Beth Hammack said that while she sees no imminent need for the U.S. central bank to change its interest rate target-setting, future cuts or even hikes were possible.

Against the yen, the dollar strengthened 0.13% to 158.98, moving closer to the 160 level that has sparked past interventions in the currency by Japanese officials. Sterling strengthened 0.04% against the greenback to $1.3567.

The surge in oil and natural gas prices has prompted traders to price in the possibility that the ECB and Bank of England will raise rates this year to temper inflation, while bringing even one Fed rate cut into doubt.

(Reporting by Chuck Mikolajczak; Additional reporting by Amanda Cooper in London and Ankur Banerjee in Singapore; Editing by Janane Venkatraman, Kirsten Donovan and Paul Simao)

By Chuck Mikolajczak