AMNA NAWAZ: The day's other headlines begin in Arizona, where the search for Nancy Guthrie, mother of "Today Show" host Savannah Guthrie, entered its second week.

And an apparent ransom deadline is just hours away.

SAVANNAH GUTHRIE, Co-Host, "The Today Show": If there's anything at all that seems strange to you, that you report it to law enforcement.

We are in an hour of desperation.

And we need your help.

AMNA NAWAZ: In a new plea today, Savannah Guthrie credited law enforcement for working tirelessly, but asked the public for its help.

Over the weekend, the Guthries said they are prepared to pay for their mother's safe return.

Investigators to date have identified no suspects or persons of interest in the case.

The U.S.

military boarded a sanctioned oil tanker in the Indian Ocean today after tracking the vessel from the Caribbean.

The Pentagon posted video of what it called a maritime interdiction aboard the Aquila II, which experts say departed Venezuela last month.

The Pentagon did not say whether it had seized the ship.

Meantime, in Venezuela, opposition leader Maria Corina Machado says an ally of hers was kidnapped in Caracas less than 12 hours after he was released from detention.

The country's top prosecutor had called for Juan Pablo Guanipa to be rearrested, but didn't say whether he had been.

Critics accuse Venezuela of backtracking on its promises to the United States to release political prisoners after President Nicolas Maduro's removal.

The Trump administration left other leaders of Maduro's regime in place.

Japan's Prime Minister Sanae Takaichi is pushing her conservative agenda forward after her party secured a supermajority in Sunday's parliamentary election.

SANAE TAKAICHI, Japanese Prime Minister (through translator): The people of our nation gave us a powerful push forward, urging us to carry through with a shift in policy, no matter what.

AMNA NAWAZ: Takaichi will be able to fast-track many of her priorities, which include cracking down on immigration, tax cuts, increased government spending, and boosting defense capabilities to stand up militarily to China.

President Trump congratulated Takaichi on social media, calling her -- quote -- "highly respected and very popular."

The two leaders will meet in Washington next month.

In San Francisco, teachers walked off the job for the first time in nearly half-a-century with no set end date, closing public schools for more than 50,000 students in the city.

(CHANTING) AMNA NAWAZ: The teachers in one of the nation's most expensive cities are demanding a 9 percent pay raise and greater help to deal with rising health care costs.

The strike comes after nearly a year of stalled talks.

Meanwhile, clear across the country, a breakthrough.

New York City nurses on a nearly monthlong strike say they have reached a tentative three-year deal for better staffing and pay with two major hospital systems.

Nurses remain on strike with a third hospital.

That's New York Presbyterian.

On Wall Street, stocks added slightly to their rally last week.

The Dow Jones industrial average barely budged, but did not just small gain.

The Nasdaq climbed by nearly 1 percent.

The S&P 500 rose by a half-percent, inching closer to record territory.

The Seattle Seahawks basked in the glow of victory today after beating the New England Patriots last night 29-13 to claim their second Super Bowl title.

Coach Mike Macdonald and game MVP Kenneth Walker III posed with the Lombardi Trophy in Santa Clara, California, today before the team returned to their hometown fans.

Walker's standout performance on the ground and the Seahawks' stifling defense held the Patriots scoreless until the fourth quarter, denying New England a record seventh championship.

The Seahawks Super Bowl parade will happen on Wednesday.

And, in Italy, Team USA has racked up two gold medals to start after the Milan-Cortina Winter Olympics opening weekend.

In the women's downhill ski, Breezy Johnson won the U.S.

its first gold of the Games, but her teammate, 41-year-old Lindsey Vonn, crashed on her run and was airlifted off the course.

Vonn was racing despite tearing her left ACL just nine days prior.

Meanwhile, on the rink, U.S.

figure skaters eked out a team win over Japan, anchored by the so-called Quad God, Ilia Malinin, who landed five quadruple jumps in one of his routines.

He will skate again in the singles events later this week.

Still to come on the "News Hour": Hong Kong publisher and democracy advocate Jimmy Lai is sentenced to decades in prison; we examine the cultural impact of Bad Bunny's Super Bowl halftime show; and Tamara Keith and Amy Walter break down the latest political headlines.