Vietnam shares shot up more than 2 percent while most other Southeast Asian stock markets treaded water ahead of a data-heavy week led by U.S. inflation figures and the First House testimony by the new head of the Federal Reserve.

U.S. inflation data, expected later in the week, could set the tone for the Fed's take on rate hikes for the year, while the spotlight will also be on the new Fed chair Jerome Powell when he faces questions from both houses of the U.S. Congress in semi-annual testimony starting Tuesday.

Vietnam index rose as much as 2.2 percent to a near 4-week high on broad-based gains, with financials and real estate stocks in the lead.

Fiachra Mac Cana, head of research at Ho Chi Minh Securities, said stocks were rising in line with a strong finish from Wall Street, which rallied on Friday following a retreat in Treasury yields.

Joint Stock Commercial Bank For Foreign Trade of Vietnam hit a record high, while property developer Vingroup rose 2.2 percent.

Singapore shares were also higher, helped by financials and industrials stocks. United Overseas Bank rose more than 1 percent to a record high, while industrial conglomerate Jardine Strategic Holdings gained 2.4 percent.

Industrial output data in the city state likely recovered in January after an unexpected fall in December, according to a Reuters poll. The data is expected later in the day.

However, Philippine shares fell about 0.6 percent to a 2-month low, dragged largely by industrials and real estate stocks. Industrial conglomerate SM Investments fell about 1.7 percent, while Ayala Land fell 2 percent to a 2-month low.

The Philippine central bank is selling its dollar reserves as a measure to manage excessive volatility driven by speculation against the peso, which is hovering near 11-year lows. The currency was also one of the worst performing among its Asian peers for 2017.