By Fabiana Negrin Ochoa and Jihye Lee

South Korea rolled out a defense plan for the won after the currency slumped to its weakest level since 2009 last week, battered by escalating Middle East tensions and rising expectations for U.S. interest-rate hikes.

At an emergency meeting over the weekend, Korean officials announced new measures to stabilize the market, warning that they stand ready to intervene to curb excessive volatility and speculative trading.

The finance ministry unveiled measures to investigate traded products affecting the exchange rate and monitor what authorities described as "speculative market-disrupting behavior," according to a statement released Sunday.

The Bank of Korea and the Financial Supervisory Service will conduct inspections, with strict measures to be imposed if warranted, according to the statement. Authorities also warned against profit-taking activities that capitalize on a weaker won.