By Stephanie Kelly and Arunima Kumar

NEW YORK (Reuters) -Oil prices rose less than 1% on Tuesday, helped by weakness in the dollar, although gains were capped as concerns mounted over a U.S. slowdown and the impact of tariffs on global economic growth.

Brent crude futures rose 56 cents, or 0.8%, to $69.84 a barrel by 10:43 a.m. EDT (1423 GMT) after falling as low as $68.63 in early trade. U.S. West Texas Intermediate crude futures gained 53 cents, or 0.8%, to $66.56 a barrel after previous declines as well.

Both benchmarks closed 1.5% lower in the previous session.

The dollar index hit a four-month low, making oil less expensive for overseas buyers. [USD/]

Oil prices, however, pared back some gains after U.S. President Donald Trump said on Tuesday he has instructed his commerce secretary to add an additional 25% tariff on all steel and aluminum imports from Canada, bringing the total tariff on those products to 50%.

"That kind of drama is adding to the volatility here," said Phil Flynn, senior analyst with the Price Futures Group.

Trump's protectionist policies have shaken global markets, imposing and delaying tariffs on major oil suppliers Canada and Mexico, while also raising duties on China, prompting retaliatory measures.

Over the weekend, Trump said a "period of transition" was likely and declined to rule out a U.S. recession.

Stocks, which crude prices often follow, extended their decline after slumping on Monday with the S&P 500 posting its biggest one-day drop since December 18 and the Nasdaq sliding 4.0%, its biggest single-day percentage drop since September 2022.

Investors await U.S. inflation data due on Wednesday for clues on the path of interest rates.

Meanwhile, investors are closely monitoring OPEC+ plans after the producer group announced plans to increase output in April.

A scaling back of U.S. tariffs would ease fears of inflation and economic contraction, said PVM analyst Tamas Varga, but the recent oil price plunge meant it was "hard to see OPEC+ going ahead with its plan and releasing oil back to the market from April."

On Friday, Russia's Deputy Prime Minister Alexander Novak told reporters that the OPEC+ producer group would go ahead with its April increase but may then consider other steps, including reducing production.

Brent is finding strong technical support at around $70 a barrel and may look to stage a bounce, said Suvro Sarkar, energy sector team lead at DBS Bank, adding that the OPEC+ supply response would be flexible, depending on market conditions.

"If oil prices fall below the $70 per barrel mark for an extended period, output hikes may be paused in our opinion. OPEC+ will also keep a careful eye on Trump's Iran and Venezuela policies," he said.

In the U.S., crude oil stockpiles were expected to have risen last week, while distillate and gasoline inventories likely fell, a preliminary Reuters poll showed on Monday.

The poll was conducted ahead of reports from the American Petroleum Institute at 4:30 p.m. EDT Tuesday and the Energy Information Administration at 10:30 a.m. EDT Wednesday.