WASHINGTON — Such topics were viewed as too politically sensitive for substantial shifts during the presidential campaign. The issues had what some U.S. officials called “AE” status, meaning any policy changes would be put off until after the election.

But with Obama winning a second term, top administration officials say they are considering whether to accelerate the withdrawal of U.S. troops from Afghanistan and offer Iran a compromise deal to curb its enrichment of uranium.

They also are considering how to work out new cooperation with China, an undertaking that Obama campaign operatives had feared might alienate swing-state voters anxious about Chinese trade policies and competition.

The administration already is taking a new direction on the Syrian conflict. Administration officials said they have begun trying to help reshape the rebel movement so it can better defend itself against military forces loyal to President Bashar Assad.

Since the conflict began early last year, the Obama administration has resisted pressure to deepen collaboration with the opposition, and has refused to supply heavy weapons to its fighters. Advocates of that approach, including some top U.S. officials, argue that unless Washington and its allies strengthen and better organize the insurgents, the administration could see Syria taken over by dangerous militants, or a victory by Assad that would strengthen his Iranian allies.

International talks about Iran’s disputed nuclear program were suspended last summer by mutual consent. The White House didn’t want to appear too conciliatory, and Iranian officials thought they couldn’t negotiate an acceptable deal while Obama was running for re-election.

Now both sides are signaling a willingness to talk one-on-one, or as part of a six-nation negotiating group. Negotiations could resume as soon as this month.

In Afghanistan, the administration is embroiled in deliberations on whether to front-load the departure of the 68,000 remaining U.S. combat troops. Though the last U.S. troops won’t leave until the end of 2014, some administration officials want to start the withdrawal early next year. Some senior military officials are seeking a delay, arguing that they need the full complement for next year’s fighting season.

Obama acknowledged early this year that he was in effect suspending some diplomatic efforts because of the political campaign. In March, he told former Russian President Dmitry Medvedev in front of an open microphone that he would have more flexibility after the election to negotiate on U.S. plans to base a missile defense system in Eastern Europe.

U.S. officials and outside experts don’t offer much hope for an agreement. The proposed system is aimed at protecting Europe from Iranian missiles. But Russia views it as a threat to its entire nuclear deterrent capability and has shown little willingness to compromise.

Obama has an incentive to make a deal because he also wants to persuade Moscow to negotiate further reductions in American and Russian nuclear weapons.