Brent crude LCOc1, the international benchmark for oil, was down 45 cents from its previous close at $55.53 per barrel at 1425 GMT. Earlier in the session, Brent had climbed to its highest since March 7 at $56.16.

U.S. West Texas Intermediate (WTI) CLc1 fell by 29 cents to $52.79 a barrel, after touching a five-week high of $53.23.

Brent has risen in each of the previous six sessions, while WTI gained for the last five days.

But analysts said there are worries that demand growth could falter, adding that other indicators were warning that the market had not yet cleared enough of its surplus to keep prices rising.

"Geopolitical tensions are bad for global demand growth," said Olivier Jakob, managing director of Petromatrix, noting rising acrimony between the United States and North Korea.

He also said the widening discount of the current Brent crude price to the contract in the next month is "basically telling you the market is not actually that tight".

U.S. crude inventories have touched record highs at the U.S. storage hub of Cushing, Oklahoma and in the U.S. Gulf Coast in recent weeks, according to U.S. government data.

A Reuters poll of analysts forecast a rise in U.S. crude inventories for a fourth straight week.

Data from industry group API is due out on Tuesday, while figures the U.S. Energy Information Administration will be released on Wednesday.

Several factors still offered support to oil prices.

Russian Energy Minister Alexander Novak said his country's output cuts would reach 250,000 barrels per day (bpd) by mid-April, TASS news agency reported. Another shutdown at Libya's largest field, Sharara, also kept oil off the market.

Russia was part of a deal between the Organization of the Petroleum Exporting Countries and other producing nations to cut output by 1.8 million bpd in the first six months of 2017.

"We have seen quite an encouraging market," said Tamas Varga, analyst with PVM Oil Associates, adding Tuesday's dip in prices looked like a temporary pause. "This market should be going higher."

Tensions in the Middle East are also supporting prices, after last week's U.S. missile strike on a Syrian air base. Syria produces only small volumes of oil, but the Middle East accounts for more than a quarter of the world's crude output.