MARSHALLTOWN, Iowa — Donald Trump declares he will boycott the last Republican debate before the Iowa caucuses, leading Texas Sen. Ted Cruz to challenge him to a one-on-one debate. Adding intrigue to the Democratic race, the White House says President Barack Obama would host Vermont Sen. Bernie Sanders for an Oval Office meeting. B

PRESIDENTIAL RACE-REPUBLICAN DEBATE-ANALYSIS

Donald Trump once again steals the show with his sudden decision to skip the final Republican presidential debate before Iowa's leadoff caucuses, ensuring that he will dominate the political discussion just days before voting begins.

PRESIDENTIAL RACE-CLINTON-SANDERS.

Hillary Clinton once again finds herself barnstorming through Iowa's frozen stretches with a diminished lead in the polls and an underdog rival on the rise. 

RANCHING STANDOFF

The FBI and Oregon State Police arrest the leaders of an armed group that has occupied a national wildlife refuge for the past three weeks, conducting a traffic stop that prompted gunfire — and one death — along a highway through the frozen high country. Militant leader Ammon Bundy and his followers were reportedly heading to a community meeting at the senior center in John Day, a Grant County town about 70 miles (113 kilometers) north of Burns, to address local residents to discuss their views on federal management of public lands. 

ZIKA VIRUS-BRAZIL

RIO DE JANEIRO — Brazil's health minister says the country is sending some 220,000 troops to battle the mosquito blamed for spreading a virus suspected of causing birth defects — but he also says the war is already being lost.

AUSTRALIA-SOUTH CHINA SEA

WASHINGTON — An international arbitration case over the disputed South China Sea that has been boycotted by China will "settle once and for all" whether artificial reefs are entitled to territorial waters, Australia's top diplomat says.