Turkey’s plunging currency is stoking anxieties on Wall Street and throughout global markets.

As the week starts, the Turkish lira has put in fresh lows against the U.S. dollar, continuing Friday’s steep downward spiral.

Turkey’s central bank on Monday made policy moves that failed to alleviate concerns among investors. It pledged to provide “all the liquidity the banks need” in a statement. It also said banks would be able to borrow foreign-exchange deposits from the central bank at a one-month maturity and one-week maturities.

Analysts said Turkey’s reluctance to raise interest rates stood out.

One dollar recently changed hands at 6.8217 lira USDTRY, +0.14% , compared with 6.4275 lira late Friday in New York, a move of about 6%. At the Turkish currency’s lows late Sunday — early Monday in Asia — one dollar bought about 7.1310.

The buck has gained 38% on the Turkish lira so far in August, stretching its year-to-date rise to 79%, according to FactSet data. It bought around only 3.80 lira in early January.

Read:3 reasons the selloff in Turkey’s lira matters for markets all over the world

The currency crisis in Ankara took a turn for the worse Friday after President Donald Trump, via Twitter, said that he authorized the doubling of steel and aluminum tariffs against the country. Turkey already is under U.S. sanctions for its detention of American evangelical pastor Andrew Brunson, who is being held on espionage charges.

During a rally over the weekend, Turkish President Recep Tayyip Erdogan struck a defiant tone on the U.S. and Trump’s recent tariff threats against what the Turkish leader described as an important ally in the North Atlantic Treaty Organization.

“You cannot tame our people with threats,” Erdogan said Saturday, during a series of speeches that he delivered in front of supporters at coastal cities near the Black Sea. “I call out to those in the United States. It is a shame. You are trading a strategic NATO ally for a pastor,” he said at one rally.

Turkey’s dilemma is causing anxieties for markets, not simply because of the crushing decline in Ankara’s currency, which could result in knock-on effects throughout other global markets, but because the country holds a strategic position on the world stage.

Check out: Turkey’s currency crisis unlikely to spread to global markets, experts say

For one, Turkey — a large, mostly Muslim nation of some 80 million people — has been a strategic alley to the U.S. in its fight against Islamic State terrorism in Syria, with which Turkey shares a border. Already that U.S.-Turkey relationship has shown signs of fraying.

In addition, Turkey has stepped up its relationship with Russia at a time when U.S.-Russian relations aren’t on a strong footing. Last year, Turkey agreed to purchase long-range missiles from Moscow.

Turkey has threatened to seek new allies as it attempts to emerge from the “interest rate, inflation spiral they are trying to force it into,” Erdogan has told supporters. Beyond Russia, Turkey has strengthened its ties with Iran, another nation with which the U.S. is at odds.

On Friday, the Dow Jones Industrial Average DJIA, +0.18% , S&P 500 index SPX, +0.30% and the Nasdaq Composite Index COMP, +0.77% all got knocked solidly lower, and the currency anxieties delivered even deeper blows to European benchmarks, where the pan-European Stoxx Europe 600 SXXP, -0.42% finished the session off 1.1% and Germany’s DAX DAX, -1.43% logged its worst one-day decline, off 2%, since June 25, according to Dow Jones Market Data.

U.S. stocks looked poised to fall again Monday, with futures for the Dow Jones Industrial Average US:YMU8, S&P 500 US:ESU8 and Nasdaq-100 US:NQU8 trading 0.5% lower. Asian equities and European markets largely lost ground.