WASHINGTON (Reuters) - Maryland became the latest state to join in legal challenges against President Donald Trump's revised temporary travel ban on Friday, with its attorney general saying it would join a lawsuit brought by Washington and other states.

Attorney General Brian Frosh said his office would formally join the suit on Monday.

"The administration persists in an effort to implement a policy that is inhumane and unconstitutional, but also makes us less safe, not more safe," Frosh said in a statement.

The new travel order, which is set to take effect on Wednesday, replaced a more sweeping ban issued on Jan. 27 that caused chaos and protests at airports.

The first order, which temporarily halted the entry of refugees and travelers from seven Muslim-majority countries, was hit by more than two dozen lawsuits.

Detractors claimed it discriminated against Muslims and violated the U.S. Constitution.

The government has said the president has wide authority to implement immigration policy and that the travel rules are necessary to protect against terrorist attacks.

"Trump's second executive order is still a Muslim ban," Frosh said in the statement.

The state of Washington brought one of the suits against the original ban, and last month a federal judge in Seattle ordered an emergency halt to the policy. That ruling was upheld by an appeals court in San Francisco.

Washington is now asking the court to apply the emergency halt to the new ban, arguing it is a veiled version of the old one.

The new order keeps a 90-day ban on travel to the United States by citizens of Iran, Libya, Somalia, Sudan, Syria and Yemen, but excludes Iraq. Refugees are still halted from entering the country for 120 days, but the new order removed an indefinite ban on all refugees from Syria.

Oregon and Minnesota also are joining Washington's challenge. Hawaii has a separate case pending against the new ban.

Frosh said the ban would make Maryland less competitive by deterring visits by academics, scientists and engineers from other countries and would hurt Maryland's universities and economy.

The U.S. Department of Justice has declined to comment on the states' cases because the litigation is pending.

(Reporting by David Alexander in Washington and Mica Rosenberg in New York; Editing by Leslie Adler)