In Europe, Tillerson faces questions about presidential support

— -- Secretary of State Rex Tillerson will meet with European allies this week to push an aggressive agenda on Ukraine, Iran, North Korea and Syria while questions swirl around his status in the Trump administration.

Tillerson arrived Monday for a week of meetings in Brussels, Vienna and Paris, amid reports that President Donald Trump has already plotted his succession plan. Trump shot down reports that Tillerson’s departure is imminent, but affirmed his weakened status, tweeting: “I call the shots.”

His disagreements with the president on how to handle hot-button issues like North Korea, Iran and Qatar have played out in public. It has led Trump to privately muse that Tillerson is “too establishment” for his cabinet, according to a senior White House official.

Some U.S. diplomats worry that Tillerson’s work abroad this week may be less effective without the appearance of the full support of the President.

“Foreign governments read that there’s tumult, that there’s a big controversy in the U.S., that he may be fired today,” a State Department official told ABC News.

“It weakens your message and your negotiating position when there’s a question if you’re going to stay.”

One senior EU diplomat told ABC News that they’re concerned that Tillerson does not speak for the president.

The Secretary of the State will likely face questions in Europe about whether the administration will move the U.S. embassy in Israel to Jerusalem. Trump is expected to make an announcement on the matter in the next few days.

Tillerson will also make the case for: countering Russian aggression in Ukraine, supporting Trump’s new Iran strategy, maximizing diplomatic pressure on North Korea by way of China and reassessing how to solve the civil war in Syria.

“This is the not the first time there’s been speculation of this kind in the media, and that has not impeded the Secretary from working very effectively with close allies and partners,” another State Department official countered.

There’s also concern about the number of key European embassies without ambassadors. These political appointees are seen as the conduit to understanding the often-conflicting Trump doctrine.

The Senate confirmed five ambassadors to Europe in early November, including U.S. Ambassador to France Jamie McCourt, U.S. Ambassador to Spain Duch Buchan, U.S. Ambassador to Croatia Robert Kohorst, U.S. Ambassador to Switzerland Edward McMullen, and U.S. Ambassador to Denmark Carla Sands.

U.S. ambassador to the United Kingdom Woody Johnson and U.S. ambassador to NATO Kay Bailey Hutchinson were confirmed earlier, but there are still key vacancies like Germany. Nominee Richard Grenell is still awaiting confirmation.

Assistant Secretary for European and Eurasian Affairs A. Wess Mitchell was recently confirmed and is traveling to Europe with the Secretary of State. But the administration has yet to submit a nominee for the ambassador posting to the European Union.

Tillerson's week ahead

Tillerson will meet with the EU’s chief diplomat and key architect of the Iran deal Federica Mogherini on Tuesday before the NATO meetings.

At NATO, Tillerson will continue Trump’s drumbeat that all members should increase their military budgets to 2 percent of their GDP, according to a senior State Department official. Some countries have already increased their budgets or vowed to reach 2 percent over time, but Germany, the largest economy in Europe, has yet to come close to reaching the mark.

At the same time, NATO allies will seek reaffirmation from Tillerson on the U.S.’s commitment to shared defense in case of an attack under Article 5.

In a speech ahead of his trip Tillerson called the U.S security relationship with Europe " ironclad," adding that, "alliances are meaningless if their members are unable or unwilling to meet their commitments." Despite those reassurances, there are still questions in some European capitals whether the U.S. will come to their defense in the event of a cyber-attack or other multi-pronged attacks.

Counterterrorism is also high up on the agenda. Tillerson will encourage better information sharing between European countries and coordination with NATO, according to another senior State Department official.

Allies will be encouraged to apply the maximum diplomatic isolation possible to North Korea after it launched its latest ballistic missile test last week, the first one that could reach the U.S. capital. They will also be encouraged to put economic pressure on China to manage North Korea, according to a senior State Department official.

Germany, the biggest country in the European Union, responded by withdrawing a lower level diplomat from Pyongyang but kept its ambassador in place. The White House has urged for complete isolation. Trump tweeted in August that Tillerson was “wasting his time” with diplomatic efforts, but there are some leaders in Chancellor Angela Merkel’s party who believe that they should keep lines open with North Korea.

The U.S. is also interested in getting an agreement to revisit the Geneva talks on how to solve the civil war in Syria. Tillerson will advocate for expanding the de-escalation zone, according to a senior State Department official. The talks have been stalled over Syrian dictator Bashar al-Assad’s role in the country. Tillerson recently said that Assad and his family have “no future” in Syria.

It’s been two months since Trump decertified Iran’s compliance with the deal. Tillerson will lobby support for Trump’s expanded strategy for countering Iran’s aggression, according to a senior State Department official.

In Vienna, Tillerson will affirm the U.S.’s support for Ukrainian sovereignty at the Organization for Security and Cooperation in Europe, according to Senior State Department official.

He will also hold a bilateral meeting with Russian foreign minister Sergei Lavrov on Thursday to push for more cooperation with North Korea, working together on defeating ISIS and solving the conflict in Ukraine.

But ahead of this meeting, Tillerson had harsh words for Russia.

“Russia continues aggressive behavior toward other regional processes and promoting non-democratic ideals,” he said last week.

“We, together with our friends in Europe, recognize the active threat of a recently resurgent Russia.”

ABC News reported Tillerson and Secretary of Defense James Mattis presented the president with a plan to arm Ukraine with anti-tank Javelin missiles. That plan has yet to be approved and passed on to Congress, but it’s seen as a bargaining chip during talks.